DS2148DK

DS2148/DS21Q48 5V E1/T1/J1 Line Interface Unit www.maxim-ic.com PIN CONFIGURATION FEATURES Complete E1, T1, or J1 Line Interface Unit (LIU) Supports Both Long- and Short-Haul Trunks Internal Software-Selectable Receive-Side Termination for 75Ω/100Ω/120Ω 5V Power Supply 32-Bit or 128-Bit Crystal-Less Jitter Attenuator Requires Only a 2.048MHz Master Clock for Both E1 and T1 with Option to Use 1.544MHz for T1 Generates the Appropriate Line Build-Outs, With and Without Return Loss, for E1 and DSX-1 and CSU Line Build-Outs for T1 AMI, HDB3, and B8ZS, Encoding/Decoding 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz Clock Output Synthesized to Recovered Clock Programmable Monitor Mode for Receiver Loopbacks and PRBS Pattern Generation/ Detection with Output for Received Errors Generates/Detects In-Band Loop Codes, 1 to 16 Bits including CSU Loop Codes 8-Bit Parallel or Serial Interface with Optional Hardware Mode Multiplexed and Nonmultiplexed Parallel Bus Supports Intel or Motorola Detects/Generates Blue (AIS) Alarms NRZ/Bipolar Interface for Tx/Rx Data I/O Transmit Open-Circuit Detection Receive Carrier Loss (RCL) Indication (G.775) High-Z State for TTIP and TRING 50mA (RMS) Current Limiter TOP VIEW 44 1 DS2148 44 TQFP DS2148 49 CSBGA (7mm x 7mm) See Section 8 for 144-pin CSBGA pinout. ORDERING INFORMATION DS2148TN Single TEMP RANGE -40°C to +85°C DS2148TN+ Single -40°C to +85°C 44 TQFP DS2148T Single 0°C to +70°C 44 TQFP DS2148T+ Single 0°C to +70°C 44 TQFP DS2148GN Single -40°C to +85°C 49 CSBGA DS2148GN Single -40°C to +85°C 49 CSBGA DS2148G Single 0°C to +70°C 49 CSBGA DS2148G+ Single 0°C to +70°C 49 CSBGA DS21Q48N Four -40°C to +85°C 144 CSBGA DS21Q48 Four 0°C to +70°C 144 CSBGA PART CHANNEL PINPACKAGE 44 TQFP + Denotes lead-free/RoHS-compliant package. Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata. 1 of 73 REV: 011206 DS2148/DS21Q48 TABLE OF CONTENTS 1 DETAILED DESCRIPTION .................................................................................................. 5 1.1 1.2 FUNCTION DESCRIPTION..................................................................................................................5 DOCUMENT REVISION HISTORY .......................................................................................................6 2 PIN DESCRIPTION............................................................................................................ 10 3 HARDWARE MODE .......................................................................................................... 23 3.1 3.2 3.3 4 REGISTER MAP .............................................................................................................................23 PARALLEL PORT OPERATION .........................................................................................................24 SERIAL PORT OPERATION..............................................................................................................24 CONTROL REGISTERS .................................................................................................... 28 4.1 DEVICE POWER-UP AND RESET .....................................................................................................31 5 STATUS REGISTERS ....................................................................................................... 34 6 DIAGNOSTICS .................................................................................................................. 39 6.1 IN-BAND LOOP CODE GENERATION AND DETECTION ......................................................................39 6.2 LOOPBACKS ..................................................................................................................................43 6.2.1 Remote Loopback (RLB) ......................................................................................................43 6.2.2 Local Loopback (LLB) ...........................................................................................................43 6.2.3 Analog Loopback (ALB) ........................................................................................................44 6.2.4 Dual Loopback (DLB)............................................................................................................44 6.3 PRBS GENERATION AND DETECTION ............................................................................................44 6.4 ERROR COUNTER ..........................................................................................................................44 6.4.1 Error Counter Update............................................................................................................45 6.5 ERROR INSERTION ........................................................................................................................45 7 ANALOG INTERFACE ...................................................................................................... 46 7.1 7.2 7.3 7.4 RECEIVER .....................................................................................................................................46 TRANSMITTER ...............................................................................................................................47 JITTER ATTENUATOR .....................................................................................................................47 G.703 SYNCHRONIZATION SIGNAL .................................................................................................48 8 DS21Q48 QUAD LIU ......................................................................................................... 55 9 DC CHARACTERISTICS ................................................................................................... 59 9.1 THERMAL CHARACTERISTICS ................................................................................................60 10 AC CHARACTERISTICS ................................................................................................... 61 11 PACKAGE INFORMATION ............................................................................................... 70 11.1 44-PIN TQFP (56-G4012-001) .....................................................................................................70 11.2 49-BALL CSGBA (7MM X 7MM) (56-G6006-001) ...........................................................................71 11.3 144-BALL CSBGA (17MM X 17MM) (56-G6011-001) .....................................................................72 2 of 73 DS2148/DS21Q48 LIST OF FIGURES Figure 1-1. DS2148 Block Diagram ............................................................................................................7 Figure 1-2. Receive Logic...........................................................................................................................8 Figure 1-3. Transmit Logic..........................................................................................................................9 Figure 2-1. Parallel Port Mode Pinout (BIS1 = 0, BIS0 = 1 or 0) (TQFP Package) ..................................21 Figure 2-2. Serial Port Mode Pinout (BIS1 = 1, BIS0 = 0) (TQFP Package) ............................................21 Figure 2-3. Hardware Mode Pinout (BIS1 = 1, BIS0 = 1) (TQFP Package) .............................................22 Figure 3-1. Serial Port Operation for Read Access (R = 1) Mode 1 .........................................................25 Figure 3-2. Serial Port Operation for Read Access Mode 2 .....................................................................25 Figure 3-3. Serial Port Operation for Read Access Mode 3 .....................................................................26 Figure 3-4. Serial Port Operation for Read Access Mode 4 .....................................................................26 Figure 3-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2..............................................27 Figure 3-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4..............................................27 Figure 7-1. Basic Interface .......................................................................................................................49 Figure 7-2. Protected Interface Using Internal Receive Termination........................................................50 Figure 7-3. Protected Interface Using External Receive Termination.......................................................51 Figure 7-4. E1 Transmit Pulse Template ..................................................................................................52 Figure 7-5. T1 Transmit Pulse Template ..................................................................................................53 Figure 7-6. Jitter Tolerance ......................................................................................................................54 Figure 7-7. Jitter Attenuation ....................................................................................................................54 Figure 8-1. 144-Pin CSBGA (17mm x 17mm) Pinout ...............................................................................58 Figure 10-1. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) .......................................................62 Figure 10-2. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) .......................................................62 Figure 10-3. Motorola Bus Timing (PBTS = 1, BIS1 = 0, BIS0 = 0)..........................................................63 Figure 10-4. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) .......................................................65 Figure 10-5. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) .......................................................65 Figure 10-6. Motorola Bus Read Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) ................................................66 Figure 10-7. Motorola Bus Write Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) ................................................66 Figure 10-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0) ................................................................................67 Figure 10-9. Receive Side Timing ............................................................................................................68 Figure 10-10. Transmit Side Timing .........................................................................................................69 3 of 73 DS2148/DS21Q48 LIST OF TABLES Table 2-1. Bus Interface Selection ...........................................................................................................10 Table 2-2. Pin Assignment in Parallel Port Mode .....................................................................................10 Table 2-3. Pin Descriptions in Parallel Port Mode (Sorted by Pin Name, DS2148T) ...............................12 Table 2-4. Pin Assignment in Serial Port Mode ........................................................................................14 Table 2-5. Pin Descriptions in Serial Port Mode (Sorted by Pin Name, DS2148T) ..................................15 Table 2-6. Pin Assignment in Hardware Mode .........................................................................................17 Table 2-7. Pin Description in Hardware Mode (Sorted by Pin Name, DS2148T) .....................................18 Table 2-8. Loopback Control in Hardware Mode ......................................................................................20 Table 2-9. Transmit Data Control in Hardware Mode ...............................................................................20 Table 2-10. Receive Sensitivity Settings ..................................................................................................20 Table 2-11. Monitor Gain Settings ............................................................................................................20 Table 2-12. Internal Rx Termination Select ..............................................................................................20 Table 2-13. MCLK Selection.....................................................................................................................20 Table 3-1. Register Map ...........................................................................................................................23 Table 4-1. MCLK Selection.......................................................................................................................29 Table 4-2. Receive Sensitivity Settings ....................................................................................................31 Table 4-3. Backplane Clock Select...........................................................................................................32 Table 4-4. Monitor Gain Settings ..............................................................................................................32 Table 4-5. Internal Rx Termination Select ................................................................................................33 Table 5-1. Received Alarm Criteria ..........................................................................................................35 Table 5-2. Receive Level Indication .........................................................................................................38 Table 6-1. Transmit Code Length .............................................................................................................40 Table 6-2. Receive Code Length..............................................................................................................40 Table 6-3. Definition of Received Errors...................................................................................................44 Table 6-4. Function of ECRS Bits and RNEG Pin ....................................................................................45 Table 7-1. Line Build-Out Select for E1 in Register CCR4 (ETS = 0).......................................................48 Table 7-2. Line Build-Out Select for T1 in Register CCR4 (ETS = 1).......................................................48 Table 7-3. Transformer Specifications for 5V Operation ..........................................................................48 Table 8-1. DS21Q48 Pin Assignment.......................................................................................................55 Table 9-1. Recommended DC Operating Conditions ...............................................................................59 Table 9-2. Capacitance ............................................................................................................................59 Table 9-3. DC Characteristics ..................................................................................................................59 Table 9-4. Thermal Characteristics—DS21Q48 CSBGA Package...........................................................60 Table 9-5. Theta-JA (θJA) vs. Airflow ........................................................................................................60 Table 10-1. AC Characteristics—Multiplexed Parallel Port (BIS1 = 0, BIS0 = 0) ....................................61 Table 10-2. AC Characteristics—Nonmultiplexed Parallel Port (BIS1 = 0, BIS0 = 1)..............................64 Table 10-3. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0) ...........................................................67 Table 10-4. AC Characteristics—Receive Side ........................................................................................68 Table 10-5. AC Characteristics—Transmit Side .......................................................................................69 4 of 73 DS2148/DS21Q48 1 DETAILED DESCRIPTION The DS2148 is a complete selectable E1 or T1 Line Interface Unit (LIU) for short- and long-haul applications. Throughout the data sheet, J1 is represented wherever T1 exists. Receive sensitivity adjusts automatically to the incoming signal and can be programmed for 0dB to 12dB or 0dB to 43dB for E1 applications and 0dB to 30dB or 0dB to 36dB for T1 applications. The device can generate the necessary G.703 E1 waveshapes in 75Ω or 120Ω applications and DSX-1 line built-outs or CSU line built-outs of 0dB, -7.5dB, -15dB, and -22.5dB for T1 applications. The crystal-less onboard jitter attenuator requires only a 2.048MHz MCLK for both E1 and T1 applications (with the option of using a 1.544MHz MCLK in T1 applications). The jitter attenuator FIFO is selectable to either 32 bits or 128 bits in depth and can be placed in either the transmit or receive data paths. An X 2.048MHz output clock synthesized to RCLK is available for use as a backplane system clock (where n = 1, 2, 4, or 8). The DS2148 has diagnostic capabilities such as loopbacks and PRBS pattern generation/detection. 16-bit loop-up and loop-down codes can be generated and detected. The device can be controlled via an 8-bit parallel muxed or nonmuxed port, serial port or used in hardware mode. The device fully meets all of the latest E1 and T1 specifications including ANSI T1.403-1999, ANSI T1.408, AT&T TR 62411, ITU G.703, G.704, G.706, G.736, G.775, G.823, I.431, O.151, O.161, ETSI ETS 300 166, JTG.703, JTI.431, JJ-20.1, TBR12, TBR13, and CTR4. 1.1 Function Description The analog AMI/HDB3 waveform off the E1 line or the AMI/B8ZS waveform off the T1 line is transformer coupled into the RTIP and RRING pins of the DS2148. The user has the option to use internal software-selectable receive-side termination for 75Ω/100Ω/120Ω applications or external termination. The device recovers clock and data from the analog signal and passes it through the jitter attenuation MUX outputting the received line clock at RCLK and bipolar or NRZ data at RPOS and RNEG. The DS2148 contains an active filter that reconstructs the analog-received signal for the nonlinear losses that occur in transmission. The receive circuitry also is configurable for various monitor applications. The device has a usable receive sensitivity of 0dB to -43dB (E1) and 0dB to -36dB (T1), which allows the device to operate on 0.63mm (22AWG) cables up to 2.5km (E1) and 6k feet (T1) in length. Data input at TPOS and TNEG is sent via the jitter attenuation MUX to the waveshaping circuitry and line driver. The DS2148 will drive the E1 or T1 line from the TTIP and TRING pins via a coupling transformer. The line driver can handle both CEPT 30/ISDN-PRI lines for E1 and long-haul (CSU) or short-haul (DSX-1) lines for T1. 5 of 73 DS2148/DS21Q48 1.2 Document Revision History 1) 2) 3) 4) 100Ω/60Ω termination reversed in Internal Rx Termination Select tables, 091799. Add DS21Q48 pinout, 092899. Correct VSM pin number in Q48 (12 x 12 BGA) from G5 to G4, 120699. Add timing diagram for Status Register (write access mode); Add mechanical dimensions for the quad version, 032900. 5) Timing diagram for Status Register (write access mode) added; elaboration on burst mode bit; add mechanical dimensions for the quad version, 050300. 6) Changes to datasheet to indicate 5V only part, 011801. 7) Added supply current measurement; added thermal characteristics of quad package, 092001. 8) Corrected typos and removed instances of 3V operation, 082504. 9) In Absolute Maximum Ratings, changed the spec for soldering temperature from IPC/JEDEC J-STD020A to J-STD-020; defined the storage temperature range as –55°C to +125°C. 10) Added lead-free packages to Ordering Information table on page 1; updated style of data sheet, 011206. 6 of 73 DS2148/DS21Q48 MCLK VSM VSS VDD Figure 1-1. DS2148 Block Diagram 2 2 JACLK Jitter Attenuator MUX Power Connections 2.048MHz to 1.544MHz PLL 16.384MHz or 8.192MHz or 4.096MHz or 2.048MHz Synthesizer MUX Local Loopback See Figure 3-2 Remote Loopback Jitter Attenuation (can be placed in either transmit or receive path) Clock / Data Recovery Peak Detect Wave Shaping TTIP CSU Filters Line Drivers Unframed All Ones Insertion TRING BIS1 Remote Loopback (Dual Mode) Analog Loopback Control and Interrupt See Figure 3-3 Control and Test Port (routed to all blocks) A0 to A4 Hardware Interface 21 INT* 8 CS* 5 D0 to D7 / AD0 to AD7 ALE(AS) RD*(DS*) RPOS RCLK RNEG RCL/LOTC TPOS TCLK TNEG Parallel Interface WR*(R/W*) SDO SDI SCLK Serial Interface BPCLK PBEO MUX MUX (the Serial, Parallel, and Hardware Interfaces share device pins) BIS0 PBTS RTIP Filter RRING Optional Termination VCO / PLL 7 of 73 HRST* TEST DS2148/DS21Q48 Figure 1-2. Receive Logic Clock Invert From Remote Loopback Routed to All Blocks RCLK CCR2.0 RPOS mux B8ZS/HDB3 Decoder NRZ Data RNEG BPV/CV/EXZ CCR1.6 4 or 8 Zero Detect 16 Zero Detect CCR2.3 CCR6.2/ RIR1.5 CCR6.0/ CCR6.1 All Ones Detector SR.4 RIR1.3 RIR1.7 Loop Code Detector SR.6 SR.7 PBEO PRBS Detector SR.0 mux CCR6.0 RIR1.6 CCR1.4 8 of 73 16-Bit Error Counter (ECR) rx bd DS2148/DS21Q48 Figure 1-3. Transmit Logic CCR3.3 CCR1.6 CCR3.4 CCR2.2 CCR3.1 PRBS Generator CCR3.0 OR Gate mux 1 To Remote Loopback BPV Insert B8ZS/ HDB3 Coder Loop Code Generator Logic Error Insert TPOS OR Gate TNEG mux 0 0 0 Clock Invert mux Routed to All Blocks JACLK (derived from MCLK) 1 mux 1 RCLK OR Gate CCR2.1 AND Gate CCR1.1 Loss Of Transmit Clock Detect CCR1.2 CCR1.0 tx bd To LOTC Output Pin 9 of 73 SR.5 TCLK DS2148/DS21Q48 2 PIN DESCRIPTION The DS2148 can be controlled in a parallel port mode, a serial port mode, or a hardware mode (Table 2-1, Table 2-2, and Table 2-3). The parallel and serial port modes are described in Section 3.2 and 3.3, and the hardware mode is described below. Table 2-1. Bus Interface Selection BIS1 0 0 0 0 1 1 BIS0 0 0 1 1 0 1 PBTS 0 1 0 1 - BUS INTERFACE TYPE Muxed Intel Muxed Motorola Nonmuxed Intel Nonmuxed Motorola Serial Port Hardware Table 2-2. Pin Assignment in Parallel Port Mode DS2148T PIN # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 DS2148G PIN# C3 C2 B1 D2 C1 D3 D1 E1 F2 F1 G1 E3 F3 G2 F4 G3 E4 G4 F5 G5 F6 G6 E5 E6 F7 D6 D5 D7 I/O I I I I I I I/O I I I I I/O I/O I/O I/O I/O I/O I/O I/O I I/O O O I I I PARALLEL PORT MODE CS RD(DS) WR(R/W) ALE(AS) NA NA A4 A3 A2 A1 A0 D7/AD7 D6/AD6 D5/AD5 D4/AD4 D3/AD3 D2/AD2 D1/AD1 D0/AD0 VSM VDD VSS INT PBEO RCL/LOTC TEST RTIP RRING 10 of 73 DS2148/DS21Q48 DS2148T PIN # 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 DS2148G PIN# C6 C7 B6 B7 A7 C5 B5 A6 B4 C4 A4 B3 A3 B2 A2 A1 I/O I I O I I O O O O O I I I I PARALLEL PORT MODE HRST MCLK BPCLK BIS0 BIS1 TTIP VSS VDD TRING RPOS RNEG RCLK TPOS TNEG TCLK PBTS 11 of 73 DS2148/DS21Q48 Table 2-3. Pin Descriptions in Parallel Port Mode (Sorted by Pin Name, DS2148T) NAME A0 to A4 PIN 11 to 7 I/O ALE(AS) 4 I BIS0/BIS1 32/33 I BPCLK 31 O CS D0/AD0 to D7/AD7 1 19 to 12 I HRST 29 I INT 23 O MCLK 30 I NA - I PBEO 24 O PBTS 44 I RCLK 40 O RD(DS) 2 I RCL/LOTC 25 O I I/O FUNCTION Address Bus. In nonmultiplexed bus operation (BIS1 = 0, BIS0 = 1), serves as the address bus. In multiplexed bus operation (BIS1 = 0, BIS0 = 0), these pins are not used and should be tied low. Address Latch Enable (Address Strobe). When using the parallel port (BIS1 = 0) in multiplexed bus mode (BIS0 = 0), serves to demultiplex the bus on a positive-going edge. In nonmultiplexed bus mode (BIS0 = 1), should be tied low. Bus Interface Select Bits 0 & 1. Used to select bus interface option. See Table 2-1 for details. Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz clock output that is referenced to RCLK selectable via CCR5.7 and CCR5.6. In hardware mode, defaults to 16.384MHz output. Active-Low Chip Select. Must be low to read or write to the device. Data Bus/Address/Data Bus. In non-multiplexed bus operation (BIS1 = 0, BIS0 = 1), serves as the data bus. In multiplexed bus operation (BIS1 = 0, BIS0 = 0), serves as an 8-bit multiplexed address/data bus. Active-Low Hardware Reset. Bringing HRST low will reset the DS2148 setting all control bits to their default state of all zeros. Active-Low Interrupt. Flags host controller during conditions and change of conditions defined in the Status Register. Active low, open drain output. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional. See Note 1 on clock accuracy at the end of this table. Not Assigned. Should be tied low. PRBS Bit Error Output. The receiver will constantly search for a 215-1 or a 220-1 PRBS depending on the ETS bit setting (CCR1.7). Remains high if out of synchronization with the PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to a logic 1. Parallel Bus Type Select. When using the parallel port (BIS1 = 0), set high to select Motorola bus timing, set low to select Intel bus timing. This pin controls the function of the RD(DS), ALE(AS), and WR(R/W) pins. If PBTS = 1 and BIS1 = 0, then these pins assume the Motorola function listed in parenthesis (). In serial port mode, this pin should be tied low. Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Active-Low Read Input (Data Strobe). DS is active low when in nonmultiplexed, Motorola mode. See the bus timing diagrams in Section 10. Receive Carrier Loss/Loss of Transmit Clock. An output which will toggle high during a receive carrier loss (CCR2.7 = 0) or will toggle high if the TCLK pin has not been toggled for 5µs ±2µs (CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware mode. 12 of 73 DS2148/DS21Q48 NAME PIN I/O RNEG 39 O RPOS 38 O RTIP/RRING 27/28 I TCLK 43 I TEST 26 I TNEG 42 I TPOS 41 I TTIP/TRING 34/37 O VDD VSM VSS WR (R/W) 21/36 20 22/35 I - 3 I FUNCTION Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out of the line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive Positive Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with bipolar data out of the line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.2 for details. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details. Transmit Clock. A 2.048MHz or 1.544MHz primary clock. Used to clock data through the transmit side formatter. Can be sourced internally by MCLK or RCLK. See Common Control Register 1 and Figure 1-3. Tri-state Control. Set high to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Useful in board level testing. Transmit Negative Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Tip and Ring. Analog line driver outputs. These pins connect via a step-up transformer to the line. See Section 5 for details. 5.0V ±5% Positive Supply Voltage Supply Mode. Should be tied high for 5V operation Signal Ground Active-Low Write Input (Read/Write). See the bus timing diagrams in Section 10. 13 of 73 DS2148/DS21Q48 Table 2-4. Pin Assignment in Serial Port Mode DS2148T PIN # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 DS2148G PIN# C3 C2 B1 D2 C1 D3 D1 E1 F2 F1 G1 E3 F3 G2 F4 G3 E4 G4 F5 G5 F6 G6 E5 E6 F7 D6 D5 D7 C6 C7 B6 B7 A7 C5 B5 A6 B4 C4 A4 B3 A3 B2 A2 A1 I/O I I I I I I I/O I I I I I/O I/O I/O I/O I/O I/O I/O I/O I I/O O O I I I I I O I I O O O O O I I I I SERIAL PORT MODE CS NA NA NA SCLK SDI SDO ICES OCES NA NA NA NA NA NA NA NA NA NA VSM VDD VSS INT PBEO RCL/LOTC TEST RTIP RRING HRST MCLK BPCLK BIS0 BIS1 TTIP VSS VDD TRING RPOS RNEG RCLK TPOS TNEG TCLK NA 14 of 73 DS2148/DS21Q48 Table 2-5. Pin Descriptions in Serial Port Mode (Sorted by Pin Name, DS2148T) NAME PIN I/O BIS0/BIS1 32/33 I BPCLK 31 O CS 1 I HRST 29 I ICES 8 I INT 23 O MCLK 30 I NA - I OCES 9 I PBEO 24 O RCLK 40 O RCL/LOTC 25 O RNEG 39 O RPOS 38 O RTIP/RRING 27/28 I SCLK 5 I FUNCTION Bus Interface Select Bits 0 & 1. Used to select bus interface option. See Table 2-1 for details. Backplane Clock. A 16.384MHz, 8.192MHz, 4.096MHz, or 2.048MHz clock output that is referenced to RCLK selectable via CCR5.7 and CCR5.6. In hardware mode, defaults to 16.384MHz output. Active-Low Chip Select. Must be low to read or write to the device. Hardware Reset. Bringing HRST low will reset the DS2148 setting all control bits to their default state of all zeros. Input Clock Edge Select. Selects whether the serial port data input (SDI) is sampled on rising (ICES =0) or falling edge (ICES = 1) of SCLK. Active-Low Interrupt. Flags host controller during conditions and change of conditions defined in the Status Register. Active low, open drain output. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional. See Note 1 on clock accuracy at the end of this table. Not Assigned. Should be tied low. Output Clock Edge Select. Selects whether the serial port data output (SDO) is valid on the rising (OCES = 1) or falling edge (OCES = 0) of SCLK. PRBS Bit Error Output. The receiver will constantly search for a 215-1 or a 220-1 PRBS depending on the ETS bit setting (CCR1.7). Remains high if out of synchronization with the PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK. PRBS bit errors can also be reported to the ECR1 and ECR2 registers by setting CCR6.2 to a logic 1. Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Receive Carrier Loss/Loss of Transmit Clock. An output which will toggle high during a receive carrier loss (CCR2.7 = 0) or will toggle high if the TCLK pin has not been toggled for 5 µs ± 2 µs (CCR2.7 = 1). CCR2.7 defaults to logic 0 when in hardware mode. Receive Negative Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with the bipolar data out of the line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive Positive Data. Updated on the rising edge (CCR2.0 = 0) or the falling edge (CCR2.0 = 1) of RCLK with bipolar data out of the line interface. Set NRZE (CCR1.6) to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details. Serial Clock. Serial bus clock input. 15 of 73 DS2148/DS21Q48 NAME PIN I/O SDI 6 I SDO 7 O TCLK 43 I TEST 26 I TNEG 42 I TPOS 41 I TTIP/TRING 34/37 O VDD VSM VSS 21/36 20 22/35 I - FUNCTION Serial Data Input. Sampled on rising edge (ICES = 0) or the falling edge (ICES = 1) of SCLK. Serial Data Output. Valid on the falling edge (OCES = 0) or the rising edge (OCES = 1) of SCLK. Transmit Clock. A 2.048 MHz or 1.544 MHz primary clock. Used to clock data through the transmit side formatter. Can be sourced internally by MCLK or RCLK. See Common Control Register 1 and Figure 1-3. Tri-State Control. Set high to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Useful in board level testing. Transmit Negative Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Positive Data. Sampled on the falling edge (CCR2.1 = 0) or the rising edge (CCR2.1 = 1) of TCLK for data to be transmitted out onto the line. Transmit Tip and Ring . Analog line driver outputs. These pins connect via a step-up transformer to the line. See Section 5 for details. 5.0V ±5% Positive Supply Voltage Supply Mode. Should be tied high for 5V operation. Signal Ground 16 of 73 DS2148/DS21Q48 Table 2-6. Pin Assignment in Hardware Mode DS2148T PIN # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 DS2148G PIN# C3 C2 B1 D2 C1 D3 D1 E1 F2 F1 G1 E3 F3 G2 F4 G3 E4 G4 F5 G5 F6 G6 E5 E6 F7 D6 D5 D7 C6 C7 B6 B7 A7 C5 B5 A6 B4 C4 A4 B3 A3 B2 A2 A1 I/O I I I I I I I/O I I I I I/O I/O I/O I/O I/O I/O I/O I/O I I/O O O I I I I I O I I O O O O O I I I I HARDWARE MODE EGL ETS NRZE SCLKE L2 L1 L0 DJA JAMUX JAS HBE CES TPD TX0 TX1 LOOP0 LOOP1 MM0 MM1 VSM VDD VSS RT1 PBEO RCL TEST RTIP RRING HRST MCLK BPCLK BIS0 BIS1 TTIP VSS VDD TRING RPOS RNEG RCLK TPOS TNEG TCLK RT0 17 of 73 DS2148/DS21Q48 Table 2-7. Pin Description in Hardware Mode (Sorted by Pin Name, DS2148T) NAME PIN I/O BIS0/BIS1 32/33 I BPCLK 31 O CES 12 I DJA 8 I EGL 1 I ETS 2 I HBE 11 I HRST 29 I JAMUX 9 I JAS 10 I L0/L1/L2 7/6/5 I LOOP0/ LOOP1 16/17 I MCLK 30 I MM0/MM1 18/19 I NA - I FUNCTION Bus Interface Select Bits 0 & 1. Used to select bus interface option. BIS0 = 1 and BIS1 = 1 selects hardware mode. Backplane Clock. 16.384MHz output. Receive & Transmit Clock Edge Select. Selects which RCLK edge to update RPOS and RNEG and which TCLK edge to sample TPOS and TNEG. 0 = update RNEG/RPOS on rising edge of RCLK; sample TPOS/TNEG on falling edge of TCLK 1 = update RNEG/RPOS on falling edge of RCLK; sample TPOS/TNEG on rising edge of TCLK Disable Jitter Attenuator 0 = jitter attenuator enabled 1 = jitter attenuator disabled Receive Equalizer Gain Limit. This pin controls the sensitivity of the receive equalizer. EGL E1 (ETS = 0) 0 = -12dB (short haul) 1 = -43dB (long haul) EGL T1 (ETS = 1) 0 = -36dB (long haul) 1 = -30dB (limited long haul) E1/T1 Select. 0 = E1 1 = T1 Receive & Transmit HDB3/B8ZS Enable. 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Hardware Reset. Bringing HRST low will reset the DS2148. Jitter Attenuator MUX. Controls the source for JACLK. See Figure 1-1 and Table 2-13. E1 (ETS = 0) JAMUX MCLK = 2.048MHz 0 T1 (ETS = 1) MCLK = 2.048MHz 1 MCLK = 1.544MHz 0 Jitter Attenuator Select 0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side Transmit LIU Waveshape Select Bits 0 & 1 [H/W Mode]. These inputs determine the waveshape of the transmitter. See Table 7-1 and Table 7-2. Loopback Select Bits 0 & 1 [H/W Mode]. These inputs determine the active loopback mode (if any). See Table 2-8. Master Clock. A 2.048MHz (±50ppm) clock source with TTL levels is applied at this pin. This clock is used internally for both clock/data recovery and for jitter attenuation. Use of a T1 1.544MHz clock source is optional. G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. Monitor Mode Select Bits 0 & 1 [H/W Mode]. These inputs determine if the receive equalizer is in a monitor mode. See Table 2-11. Not Assigned. Should be tied low. 18 of 73 DS2148/DS21Q48 NAME PIN I/O NRZE 3 I PBEO 24 O RCLK 40 O RCL 25 O RNEG 39 O RPOS 38 O RT0/RT1 44/23 I RTIP/ RRING 27/28 I SCLKE 4 I TCLK 43 I TEST 26 I TNEG 42 I TPD 13 I TPOS 41 I TTIP/ TRING 34/37 O TX0/TX1 14/15 I VDD VSM VSS 21/36 20 22/35 I - FUNCTION NRZ Enable [H/W Mode] 0 = Bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive going pulse when device receives a BPV, CV, or EXZ. PRBS Bit Error Output. The receiver will constantly search for a QRSS (T1) or a 215-1 (E1) PRBS depending on whether T1 or E1 mode is selected. Remains high if out of synchronization with the PRBS pattern. Goes low when synchronized to the PRBS pattern. Any errors in the received pattern after synchronization will cause a positive going pulse (with same period as E1 or T1 clock) synchronous with RCLK. Receive Clock. Buffered recovered clock from the line. Synchronous to MCLK in absence of signal at RTIP and RRING. Receive Carrier Loss. An output which will toggle high during a receive carrier loss. Receive Negative Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with the bipolar data out of the line interface. Set NRZE to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive Positive Data. Updated on the rising edge (CES = 0) or the falling edge (CES = 1) of RCLK with bipolar data out of the line interface. Set NRZE pin to a one for NRZ applications. In NRZ mode, data will be output on RPOS while a received error will cause a positive-going pulse synchronous with RCLK at RNEG. See Section 6.4 for details. Receive LIU Termination Select Bits 0 & 1 [H/W Mode]. These inputs determine the receive termination. See Table 2-12. Receive Tip and Ring. Analog inputs for clock recovery circuitry. These pins connect via a 1:1 transformer to the line. See Section 5 for details. Receive & Transmit Synchronization Clock Enable. 0 = disable 2.048MHz synchronization transmit and receive mode 1 = enable 2.048MHz synchronization transmit and receive mode Transmit Clock. A 2.048MHz or 1.544MHz primary clock. Used to clock data through the transmit side formatter. Tri-State Control. Set high to tri-state all outputs and I/O pins (including the parallel control port). Set low for normal operation. Useful in board level testing. Transmit Negative Data. Sampled on the falling edge (CES = 0) or the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line. Transmit Power-Down 0 = normal transmitter operation 1 = powers down the transmitter and tri-states the TTIP and TRING pins Transmit Positive Data. Sampled on the falling edge (CES = 0) or the rising edge (CES = 1) of TCLK for data to be transmitted out onto the line. Transmit Tip and Ring. Analog line driver outputs. These pins connect via a step-up transformer to the line. See Section 5 for details. Transmit Data Source Select Bits 0 & 1 [H/W Mode]. These inputs determine the source of the transmit data. See Table 2-9. 5.0V ±5% Positive Supply Voltage Supply Mode. Should be tied high for 5V operation Signal Ground Note 1: G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. 19 of 73 DS2148/DS21Q48 Table 2-8. Loopback Control in Hardware Mode LOOPBACK Remote Loopback Local Loopback Analog Loopback No Loopback SYMBOL RLB LLB ALB – CONTROL BIT CCR6.6 CCR6.7 CCR6.4 – LOOP1 1 1 0 0 LOOP0 1 0 1 0 Table 2-9. Transmit Data Control in Hardware Mode TRANSMIT DATA SYMBOL Transmit Unframed All Ones Transmit Alternating Ones and Zeros Transmit PRBS TPOS and TNEG TUA1 TAOZ TPRBSE – CONTROL BIT CCR3.7 CCR3.5 CCR3.4 – TX1 TX0 1 1 0 0 1 0 1 0 Table 2-10. Receive Sensitivity Settings EGL (CCR4.4) 0 1 1 0 ETS (CCR1.7) 0 (E1) 0 (E1) 1 (T1) 1 (T1) RECEIVE SENSITIVITY -12dB (short haul) -43dB (long haul) -30dB (limited long haul) -36dB (long haul) Table 2-11. Monitor Gain Settings MM1 (CCR5.5) 0 0 1 1 MM0 (CCR5.4) 0 1 0 1 INTERNAL LINEAR GAIN BOOST (dB) Normal operation (no boost) 20 26 32 Table 2-12. Internal Rx Termination Select RT1 (CCR5.1) 0 0 1 1 RT0 (CCR5.0) 0 1 0 1 INTERNAL RECEIVE TERMINATION CONFIGURATION Internal receive-side termination disabled Internal receive-side 120Ω enabled Internal receive-side 100Ω enabled Internal receive-side 75Ω enabled Table 2-13. MCLK Selection MCLK 2.048MHz 2.048MHz 1.544MHz JAMUX (CCR1.3) 0 1 0 ETS (CCR1.7) 0 1 1 20 of 73 DS2148/DS21Q48 Figure 2-1. Parallel Port Mode Pinout (BIS1 = 0, BIS0 = 1 or 0) (TQFP Package) 34 TTIP 35 VSS 36 VDD 37 TRING 38 RPOS 39 RNEG 40 RCLK 41 TPOS 42 TNEG 43 TCLK 44 PBTS 1 CS* BIS1 33 tie low 2 RD (DS) BIS0 32 tie low (MUX) or high (non-MUX) 3 WR* (R/W*) BPCLK 31 4 ALE (AS) MCLK 30 DS2148 Parallel Port Operation 5 NA 6 NA 7 A4 HRST* 29 RRING 28 RTIP 27 (Note: tie all NA pins low) 8 A3 TEST 26 9 A2 RCL/LOTC 25 10 A1 PBEO 24 INT* 23 VSS 22 VDD 21 VSM 20 AD0/D0 19 AD1/D1 18 AD2/D2 17 AD3/D3 16 AD4/D4 15 AD5/D5 14 AD6/D6 13 AD7/D7 12 11 A0 tie high Figure 2-2. Serial Port Mode Pinout (BIS1 = 1, BIS0 = 0) (TQFP Package) tie low 34 TTIP 35 VSS 36 VDD 37 TRING 38 RPOS 39 RNEG 40 RCLK 41 TPOS 42 TNEG 43 TCLK 44 PBTS 1 CS* BIS1 33 tie high 2 NA BIS0 32 tie low 3 NA BPCLK 31 4 NA MCLK 30 DS2148 Serial Port Operation 5 SCLK 6 SDI 7 SDO HRST* 29 RRING 28 RTIP 27 (Note: tie all NA pins low) TEST 26 8 ICES RCL/LOTC 25 9 OCES 10 NA PBEO 24 11 NA INT* 23 VSS 22 VDD 21 VSM 20 NA 19 NA 18 NA 17 NA 16 NA 15 NA 14 NA 13 NA 12 tie high 21 of 73 DS2148/DS21Q48 Figure 2-3. Hardware Mode Pinout (BIS1 = 1, BIS0 = 1) (TQFP Package) 34 TTIP 35 VSS 36 VDD 37 TRING 38 RPOS 39 RNEG 40 RCLK 41 TPOS 42 TNEG 43 TCLK 44 RT0 1 EG L BIS1 33 tie high 2 ET S BIS0 32 tie high 3 NRZE BPCLK 31 4 SCLKE M CLK 30 D S2148 H ardware Operation 5 L2 6 L1 HRST* 29 RRING 28 7 L0 RTIP 27 8 DJA TEST 26 9 JAM UX RCL 25 11 HBE RT1 23 VSS 22 VDD 21 VSM 20 tie high 22 of 73 MM1 19 MM0 18 TX1 15 TX0 14 TPD 13 CES 12 LOOP1 17 PBEO 24 LOOP0 16 10 JAS DS2148/DS21Q48 3 HARDWARE MODE In hardware mode (BIS1 = 1, BIS0 = 1), pins 1-19, 23, 25, 31, and 44 are redefined to be used for initializing the DS2148. BPCLK (pin 31) defaults to a 16.384MHz output when in hardware mode. The RCL/LOTC (pin 25) is designated to RCL when in hardware mode. JABDS (CCR4.2) defaults to logic 0. The RHBE (CCR2.3) and THBE (CCR2.2) control bits are combined and controlled by HBE at pin 11 while the RSCLKE (CCR5.3) and TSCLKE (CCR5.2) bits are combined and controlled by SCLKE at pin 4. TCES (CCR2.1) and RCES (CCR2.0) are combined and controlled by CES at pin 12. The transmitter functions are combined and controlled by TX1 (pin 15) and TX0 (pin 14). LOOP1 (pin 17) and LOOP0 (pin 16) control the loopback functions. All other control bits default to the logic 0 setting. 3.1 Register Map Table 3-1. Register Map NAME CCR1 CCR2 CCR3 CCR4 CCR5 CCR6 SR IMR RIR1 RIR2 IBCC TCD1 TCD2 RUPCD1 RUPCD2 RDNCD1 RDNCD2 ECR1 ECR2 TEST1 TEST2 TEST3 – REGISTER NAME Common Control Register 1 Common Control Register 2 Common Control Register 3 Common Control Register 4 Common Control Register 5 Common Control Register 6 Status Register Interrupt Mask Register Receive Information Register 1 Receive Information Register 2 In-Band Code Control Register Transmit Code Definition Register 1 Transmit Code Definition Register 2 Receive Up Code Definition Register 1 Receive Up Code Definition Register 2 Receive Down Code Definition Register 1 Receive Down Code Definition Register 2 Error Count Register 1 Error Count Register 2 Test 1 Test 2 Test 3 – R/W PARALLEL PORT MODE R/W R/W R/W R/W R/W R/W R R/W R R R/W R/W R/W R/W R/W R/W R/W R R R/W R/W R/W – 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h Note 1 SERIAL PORT MODE (Notes 2–5) (msb) (lsb) B000 000A B000 001A B000 010A B000 011A B000 100A B000 101A B000 110A B000 111A B001 000A B001 001A B001 010A B001 011A B001 100A B001 101A B001 110A B001 111A B010 000A B010 001A B010 010A B010 011A B010 100A B010 101A – NOTES: 1) Register addresses 16h to 1Fh do not exist. 2) In the Serial Port Mode, the LSB is on the right hand side. 3) In the Serial Port Mode, data is read and written LSB first. 4) In the Serial Port Mode, the A bit (the LSB) determines whether the access is a read (A = 1) or a write (A = 0). 5) In the Serial Port Mode, the B bit (the MSB) determines whether the access is a burst access (B = 1) or a single register access (B = 0). 23 of 73 DS2148/DS21Q48 3.2 Parallel Port Operation When using the parallel interface on the DS2148 (BIS1 = 0) the user has the option for either multiplexed bus operation (BIS1 = 0, BIS0 = 0) or nonmultiplexed bus operation (BIS1 = 0, BIS0 = 1). The DS2148 can operate with either Intel or Motorola bus timing configurations. If the PBTS pin is tied low, Intel timing will be selected; if tied high, Motorola timing will be selected. All Motorola bus signals are listed in parentheses. See the timing diagrams in Section 10 for more details. 3.3 Serial Port Operation Setting BIS1 = 1 and BIS0 = 0 enables the serial bus interface on the DS2148. Port read/write timing is unrelated to the system transmit and receive timing, allowing asynchronous reads or writes by the host. See Section 10 for the AC timing of the serial port. All serial port accesses are LSB first. See Figure 3-1, Figure 3-2, Figure 3-3, and Figure 3-4 for more details. Reading or writing to the internal registers requires writing one address/command byte prior to transferring register data. The first bit written (LSB) of the address/command byte specifies whether the access is a read (1) or a write (0). The next 5 bits identify the register address. Bit 7 is reserved and must be set to 0 for proper operation. The last bit (MSB) of the address/command byte is the burst mode bit. When the burst bit is enabled (B = 1) and a READ operation is performed, addresses 0 through 15h are read sequentially, starting at address 0h. And when the burst bit is enabled and a WRITE operation is performed, addresses 0 through 16h are written sequentially, starting at address 0h. Burst operation is stopped once address 15h is read. See Figure 3-5 and Figure 3-6 for more details. All data transfers are initiated by driving the CS input low. When input clock-edge select (ICES) is low, input data is latched on the rising edge of SCLK and when ICES is high, input data is latched on the falling edge of SCLK. When output clock-edge select (OCES) is low, data is output on the falling edge of SCLK and when OCES is high, data is output on the rising edge of SCLK. Data is held until the next falling or rising edge. All data transfers are terminated if the CS input transitions high. Port control logic is disabled and SDO is tri-stated when CS is high. 24 of 73 DS2148/DS21Q48 Figure 3-1. Serial Port Operation for Read Access (R = 1) Mode 1 ICES = 1 (sample SDI on the falling edge of SCLK) OCES = 1 (update SDO on rising edge of SCLK) SCLK 1 2 3 4 5 6 A0 A1 A2 A3 A4 7 8 9 10 11 12 13 14 15 D0 D1 D2 D3 D4 D5 D6 16 CS SDI 1 0 B (lsb) (msb) READ ACCESS ENABLED SDO D7 (lsb) (msb) Figure 3-2. Serial Port Operation for Read Access Mode 2 ICES = 1 (sample SDI on the falling edge of SCLK) OCES = 0 (update SDO on falling edge of SCLK) SCLK 1 2 3 4 5 6 A0 A1 A2 A3 A4 7 8 9 10 11 12 13 14 15 16 CS SDI 1 (lsb) SDO 0 B (msb) D0 (lsb) 25 of 73 D1 D2 D3 D4 D5 D6 D7 (msb) DS2148/DS21Q48 Figure 3-3. Serial Port Operation for Read Access Mode 3 ICES = 0 (sample SDI on the rising edge of SCLK) OCES = 0 (update SDO on falling edge of SCLK) SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 CS SDI A0 1 A1 A2 A3 A4 0 B (lsb) (msb) SDO D0 D1 D2 D3 D4 D5 D6 (lsb) D7 (msb) Figure 3-4. Serial Port Operation for Read Access Mode 4 ICES = 0 (sample SDI on the rising edge of SCLK) OCES = 1 (update SDO on rising edge of SCLK) SCLK 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 D0 D1 D2 D3 D4 D5 D6 16 CS SDI 1 SDO (lsb) A0 A1 A2 A3 A4 0 B (msb) (lsb) D0 26 of 73 D7 (msb) DS2148/DS21Q48 Figure 3-5. Serial Port Operation for Write Access (R = 0) Modes 1 and 2 ICES = 1 (sample SDI on the falling edge of SCLK) SCLK 1 2 3 4 5 6 A0 A1 A2 A3 A4 7 8 9 10 11 12 13 14 15 16 B DO D1 D2 D3 D4 D5 D6 (msb) (lsb) CS SDI 0 0 (lsb) D7 (msb) WRITE ACCESS ENABLED SDO Figure 3-6. Serial Port Operation for Write Access (R = 0) Modes 3 and 4 ICES = 0 (sample SDI on the rising edge of SCLK) SCLK 1 2 3 4 5 6 0 A0 A1 A2 A3 A4 7 8 9 10 11 12 13 14 15 16 CS SDI (lsb) 0 B DO (msb) (lsb) D1 WRITE ACCESS ENABLED SDO 27 of 73 D2 D3 D4 D5 D6 D7 (msb) DS2148/DS21Q48 4 CONTROL REGISTERS CCR1 (00H): COMMON CONTROL REGISTER 1 (MSB) ETS NRZE RCLA SYMBOL POSITION ETS CCR1.7 NRZE CCR1.6 RCLA CCR1.5 ECUE CCR1.4 JAMUX CCR1.3 TTOJ CCR1.2 TTOR CCR1.1 LOTCMC CCR1.0 ECUE JAMUX TTOJ TTOR (LSB) LOTCMC DESCRIPTION E1/T1 Select. 0 = E1 1 = T1 NRZ Enable. 0 = Bipolar data at RPOS/RNEG and TPOS/TNEG 1 = NRZ data at RPOS and TPOS or TNEG; RNEG outputs a positive going pulse when device receives a BPV, CV, or EXZ. See Figure 1-2 and Figure 1-3. Receive Carrier Loss Alternate Criteria. 0 = RCL declared upon 255 (E1) or 192 (T1) consecutive zeros 1 = RCL declared upon 2048 (E1) or 1544 (T1) consecutive zeros Error Counter Update Enable. A 0 to 1-transition forces the next clock cycle to load the error counter registers with the latest counts and reset the counters. The user must wait a minimum of two clocks cycles (976ns for E1 and 1296ns for T1) before reading the error count registers to allow for a proper update. See Section 4 and Figure 1-2 for details. Jitter Attenuator MUX. Controls the source for JACLK. See Figure 1-1. 0 = JACLK sourced from MCLK (2.048MHz or 1.544MHz at MCLK) 1 = JACLK sourced from internal PLL (2.048MHz at MCLK) TCLK to JACLK. Internally connects TCLK to JACLK. See Figure 1-3. 0 = disabled 1 = enabled TCLK to RCLK. Internally connects TCLK to RCLK. See Figure 1-3. 0 = disabled 1 = enabled Loss Of Transmit Clock Mux Control. Determines whether the transmit logic should switch to JACLK if the TCLK input should fail to transition. See Figure 1-3. 0 = do not switch to JACLK if TCLK stops 1 = switch to JACLK if TCLK stops 28 of 73 DS2148/DS21Q48 Table 4-1. MCLK Selection JAMUX (CCR1.3) 0 1 0 MCLK 2.048MHz 2.048MHz 1.544MHz ETS (CCR1.7) 0 1 1 CCR2 (01H): COMMON CONTROL REGISTER 2 (MSB) P25S N/A SCLD SYMBOL POSITION P25S CCR2.7 SCLD CCR2.6 CCR2.5 CLDS CCR2.4 RHBE CCR2.3 THBE CCR2.2 TCES CCR2.1 RCES CCR2.0 CLDS RHBE THBE TCES (LSB) RCES DESCRIPTION Pin 25 Select. Forced to logic 0 in hardware mode. 0 = toggles high during a Receive Carrier Loss condition 1 = toggles high if TCLK does not transition for at least 5µs. Not Assigned. Should be set to zero when written to. Short Circuit Limit Disable (ETS = 0). Controls the 50mA (RMS) current limiter. 0 = enable 50mA current limiter 1 = disable 50mA current limiter Custom Line Driver Select. Setting this bit to a one will redefine the operation of the transmit line driver. When this bit is set to a one and CCR4.5 = CCR4.6 = CCR4.7 = 0, then the device will generate a square wave at the TTIP and TRING outputs instead of a normal waveform. When this bit is set to a one and CCR4.5 = CCR4.6 = CCR4.7 ≠ 0, then the device will force TTIP and TRING outputs to become open drain drivers instead of their normal push-pull operation. This bit should be set to zero for normal operation of the device. Contact the factory for more details on how to use this bit. Receive HDB3/B8ZS Enable. See Figure 1-2. 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Transmit HDB3/B8ZS Enable. See Figure 1-3. 0 = enable HDB3 (E1)/B8ZS (T1) 1 = disable HDB3 (E1)/B8ZS (T1) Transmit Clock Edge Select. Selects which TCLK edge to sample TPOS and TNEG. See Figure 1-3. 0 = sample TPOS and TNEG on falling edge of TCLK 1 = sample TPOS and TNEG on rising edge of TCLK Receive Clock Edge Select. Selects which RCLK edge to update RPOS and RNEG. See Figure 1-2. 0 = update RPOS and RNEG on rising edge of RCLK 1 = update RPOS and RNEG on falling edge of RCLK 29 of 73 DS2148/DS21Q48 CCR3 (02H): COMMON CONTROL REGISTER 3 (MSB) TUA1 ATUA1 TAOZ SYMBOL POSITION TUA1 CCR3.7 ATUA1 CCR3.6 TAOZ CCR3.5 TPRBSE CCR3.4 TLCE CCR3.3 LIRST CCR3.2 IBPV CCR3.1 IBE CCR3.0 TPRBSE TLCE LIRST IBPV (LSB) IBE DESCRIPTION Transmit Unframed All Ones. The polarity of this bit is set such that the device will transmit an all ones pattern on power-up or device reset. This bit must be set to a one to allow the device to transmit data. The transmission of this data pattern is always timed off of the JACLK (See Figure 1-1). 0 = transmit all ones at TTIP and TRING 1 = transmit data normally Automatic Transmit Unframed All Ones. Automatically transmit an unframed all ones pattern at TTIP and TRING during a receive carrier loss (RCL) condition or a receive all ones condition. 0 = disabled 1 = enabled Transmit Alternate Ones and Zeros. Transmit a …101010… pattern at TTIP and TRING. The transmission of this data pattern is always timed off of TCLK (See Figure 1-1). 0 = disabled 1 = enabled Transmit PRBS Enable. Transmit a 215 - 1 (E1) or a 220 - 1 (T1) PRBS at TTIP and TRING. See Figure 1-3. 0 = disabled 1 = enabled Transmit Loop Code Enable. Enables the transmit side to transmit the loop up code in the Transmit Code Definition registers (TCD1 and TCD2). See Section 4 and Figure 1-3 for details. 0 = disabled 1 = enabled Line Interface Reset. Setting this bit from a zero to a one will initiate an internal reset that resets the clock recovery state machine and re-centers the jitter attenuator. Normally this bit is only toggled on power-up. Must be cleared and set again for a subsequent reset. Insert BPV. A 0 to 1 transition on this bit will cause a single Bipolar Violation (BPV) to be inserted into the transmit data stream. Once this bit has been toggled from a 0 to a 1, the device waits for the next occurrence of three consecutive ones to insert the BPV. This bit must be cleared and set again for a subsequent error to be inserted. See Figure 1-3. Insert Bit Error. A 0 to 1 transition on this bit will cause a single logic error to be inserted into the transmit data stream. This bit must be cleared and set again for a subsequent error to be inserted. See Figure 1-3. 30 of 73 DS2148/DS21Q48 4.1 Device Power-Up and Reset The DS2148 will reset itself upon power-up, setting all writeable registers to 00h and clearing the status and information registers. CCR3.7 (TUA1) = 0 results in the LIU transmitting unframed all ones. After the power supplies have settled following power-up, initialize all control registers to the desired settings, then toggle the LIRST bit (CCR3.2). The DS2148 can be reset at anytime to the default settings by bringing HRST (pin 29) low (level triggered) or by powering down and powering up again. CCR4 (03H): COMMON CONTROL REGISTER 4 (MSB) L2 L1 L0 SYMBOL POSITION L2 CCR4.7 L1 CCR4.6 L0 CCR4.5 EGL CCR4.4 JAS CCR4.3 JABDS CCR4.2 DJA CCR4.1 TPD CCR4.0 EGL JAS ETS (CCR1.7) 0 (E1) 0 (E1) 1 (T1) 1 (T1) DJA DESCRIPTION Line Build-Out Select Bit 2. Sets the transmitter build out (Table 7-1 for E1 and Table 7-2 for T1) Line Build-Out Select Bit 1. Sets the transmitter build out (Table 7-1 for E1 and Table 7-2 for T1) Line Build-Out Select Bit 0. Sets the transmitter build out (Table 7-1 for E1 and Table 7-2 for T1) Receive Equalizer Gain Limit. This bit controls the sensitivity of the receive equalizer (Table 4-2). Jitter Attenuator Select. 0 = place the jitter attenuator on the receive side 1 = place the jitter attenuator on the transmit side Jitter Attenuator Buffer Depth Select. 0 = 128 bits 1 = 32 bits (use for delay sensitive applications) Disable Jitter Attenuator. 0 = jitter attenuator enabled 1 = jitter attenuator disabled Transmit Power-Down. 0 = normal transmitter operation 1 = powers down the transmitter and tri-states the TTIP and TRING pins Table 4-2. Receive Sensitivity Settings EGL (CCR4.4) 0 1 1 0 JABDS (LSB) TPD RECEIVE SENSITIVITY -12dB (short haul) -43dB (long haul) -30dB (limited long haul) -36dB (long haul) 31 of 73 DS2148/DS21Q48 CCR5 (04H): COMMON CONTROL REGISTER 5 (MSB) BPCS1 BPCS0 MM1 SYMBOL POSITION BPCS1 BPCS0 MM1 MM0 RSCLKE CCR5.7 CCR5.6 CCR5.5 CCR5.4 CCR5.3 TSCLKE CCR5.2 RT1 RT0 CCR5.1 CCR5.0 MM0 RSCLKE BPCS0 (CCR5.6) 0 1 0 1 Backplane Clock Select 1. See Table 4-3 for details. Backplane Clock Select 0. See Table 4-3 for details. Monitor Mode 1. See Table 4-4. Monitor Mode 0. See Table 4-4. Receive Synchronization Clock Enable. This control bit determines whether the line receiver should handle normal T1/E1 signals or a synchronized signal. E1 mode: 0 = receive normal E1 signal (Section 6 of G.703) 1 = receive 2.048 MHz synchronization signal (Section 10 of G.703) T1 mode: 0 = receive normal T1 signal 1 = receive 1.544 MHz synchronization signal Transmit Synchronization Clock Enable. This control bit determines whether the transmitter should transmit normal T1/E1 signals or a synchronized signal. E1 mode: 0 = transmit normal E1 signal (Section 6 of G.703) 1 = transmit 2.048 MHz synchronization signal (Section 10 of G.703) T1 mode: 0 = transmit normal T1 signal 1 = transmit 1.544 MHz synchronization signal Receive Termination 1. See Table 4-5 for details. Receive Termination 0. See Table 4-5 for details. BPCLK FREQUENCY 16.384MHz 8.192MHz 4.096MHz 2.048MHz Table 4-4. Monitor Gain Settings MM1 (CCR5.5) 0 0 1 1 MM0 (CCR5.4) 0 1 0 1 RT1 DESCRIPTION Table 4-3. Backplane Clock Select BPCS1 (CCR5.7) 0 0 1 1 TSCLKE (LSB) RT0 INTERNAL LINEAR GAIN BOOST (dB) Normal operation (no boost) 20 26 32 32 of 73 DS2148/DS21Q48 Table 4-5. Internal Rx Termination Select RT1 (CCR5.1) 0 0 1 1 RT0 (CCR5.0) 0 1 0 1 INTERNAL RECEIVE TERMINATION CONFIGURATION Internal receive-side termination disabled Internal receive-side 120Ω enabled Internal receive-side 100Ω enabled Internal receive-side 75Ω enabled CCR6 (05H): COMMON CONTROL REGISTER 6 (MSB) LLB RLB ARLBE SYMBOL POSITION LLB CCR6.7 RLB CCR6.6 ARLBE CCR6.5 ALB CCR6.4 ALB RJAB ECRS2 ECRS1 (LSB) ECRS0 DESCRIPTION Local Loopback. In Local Loopback (LLB), transmit data will be looped back to the receive path passing through the jitter attenuator if it is enabled. Data in the transmit path will act as normal. See Figure 1-1 and Section 6.2.2 for details. 0 = loopback disabled 1 = loopback enabled Remote Loopback. In Remote Loopback (RLB), data output from the clock/data recovery circuitry will be looped back to the transmit path passing through the jitter attenuator if it is enabled. Data in the receive path will act as normal while data presented at TPOS and TNEG will be ignored. See Figure 1-1 and Section 6.2.1 for details. 0 = loopback disabled 1 = loopback enabled Automatic Remote Loopback Enable and Reset. When this bit is set high, the device will automatically go into remote loopback when it detects loop-up code programmed into the receive loop-up code definition registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds and it will also set the RIR2.1 status bit. Once in a RLB state, it will remain in this state until it has detected the loop code programmed into the receive loop-down code definition registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds at which point it will force the device out of RLB and clear RIR2.1. Toggling this bit from a 1 to a 0 can reset the automatic RLB circuitry. The action of the automatic remote loopback circuitry is logically ORed with the RLB (CCR6.6) control bit (i.e., either one can cause a RLB to occur). Analog Loopback. In analog loopback (ALB), signals at TTIP and TRING will be internally connected to RTIP and RRING. The incoming signals, from the line, at RTIP and RRING will be ignored. The signals at TTIP and TRING will be transmitted as normal. See Figure 1-1 and Section 6.2.3 for more details. 0 = loopback disabled 1 = loopback enabled 33 of 73 DS2148/DS21Q48 SYMBOL POSITION RJAB CCR6.3 ECRS2 ECRS1 ECRS0 CCR6.2 CCR6.1 CCR6.0 DESCRIPTION RCLK Jitter Attenuator Bypass. This control bit allows the recovered received clock and data to bypass the jitter attenuation while still allowing the BPCLK output to use the jitter attenuator. See Figure 1-1 and Section 7.1 for details. 0 = disabled 1 = enabled Error Count Register Select 2. See Section 6.4 for details. Error Count Register Select 1. See Section 6.4 for details. Error Count Register Select 0. See Section 6.4 for details. 5 STATUS REGISTERS There are three registers that contain information on the current real-time status of the device, status register (SR), and receive information registers 1 and 2 (RIR1/RIR2). When a particular event has occurred (or is occurring), the appropriate bit in one of these three registers will be set to a one. Some of the bits in SR, RIR1, and RIR2 are latched bits and some are real-time bits. The register descriptions below list which status bits are latched and which are real-time bits. For latched status bits, when an event or an alarm occurs the bit is set to a one and will remain set until the user reads that bit. The bit will be cleared when it is read and it will not be set again until the event has occurred again. Two of the latched status bits (RUA1 & RCL) will remain set after reading if the alarm is still present. The user will always precede a read of any of the three status registers with a write. The byte written to the register will inform the DS2148 which bits the user wishes to read and have cleared. The user will write a byte to one of these registers with a one in the bit positions to be read and a zero in the other bit positions. When a one is written to a bit location, that location will be updated with the latest information. When a zero is written to a bit position, that bit position will not be updated and the previous value will be held. A write to the status and information registers will be immediately followed by a read of the same register. The read result should be logically ANDed with the mask byte that was just written and this value should be written back into the same register to ensure that bit does indeed clear. This second write step is necessary because the alarms and events in the status registers occur asynchronously with respect to their access via the parallel port. This write-read-write scheme allows an external microcontroller or microprocessor to individually poll certain bits without disturbing the other bits in the register. This operation is key in controlling the DS2148 with higher-order software languages. The bits in the SR register have the unique ability to initiate a hardware interrupt via the INT output pin. Each of the alarms and events in the SR can be either masked or unmasked from the interrupt pin via the interrupt mask register (IMR). The interrupts caused by the RCL, RUA1, and LOTC bits in SR act differently than the interrupts caused by the other status bits in SR. The RCL, RUA1 and LOTC bits will force the INT pin low whenever they change state (i.e., go active or inactive). The INT pin will be allowed to return high (if no other interrupts are present) when the user reads the alarm bit that caused the interrupt to occur even if the alarm is still present. The other status bits in SR can force the INT pin low when they are set. The INT pin will be allowed to return high (if no other interrupts are present) when the user reads the event bit that caused the interrupt to occur. 34 of 73 DS2148/DS21Q48 Table 5-1. Received Alarm Criteria ALARM E1/T1 RUA1 E1 RUA1 T1 RCL1 E1 1 RCL T1 SET CRITERIA Less than two zeros in two frames (512 bits) Over a 3ms window, five or less zeros are received 255 (or 2048)2 consecutive zeros received (G.775) 192 (or 1544)2 consecutive zeros are received CLEAR CRITERIA More than two zeros in two frames (512 bits) Over a 3ms window, six or more zeros are received In 255 bit times, at least 32 ones are received 14 or more ones out of 112 possible bit positions are received starting with the first one received NOTES: 1) Receive carrier loss (RCL) is also known as loss-of-signal (LOS) or Red Alarm in T1. 2) See CCR1.5 for details. SR (06H): STATUS REGISTER (MSB) LUP LDN LOTC SYMBOL POSITION LUP (latched) SR.7 LDN (latched) SR.6 LOTC (real time) RUA1 (latched) RCL (latched) TCLE (real time) SR.5 TOCD (real time) PRBSD (real time) SR.4 SR.3 SR.2 SR.1 SR.0 RUA1 RCL TCLE TOCD (LSB) PRBSD DESCRIPTION Loop Up Code Detected. Set when the loop up code defined in registers RUPCD1 and RUPCD2 is being received. See Section 4 for details. Loop Down Code Detected. Set when the loop down code defined in registers RDNCD1 and RDNCD2 is being received. See Section 4 for details. Loss of Transmit Clock. Set when the TCLK pin has not transitioned for 5µsec (±2µsec). Will force the LOTC pin high. Receive Unframed All Ones. Set when an unframed all ones code is received at RRING and RTIP. See Table 5-1 for details. Receive Carrier Loss. Set when a receive carrier loss condition exists at RRING and RTIP. See Table 5-1 for details. Transmit Current Limit Exceeded. Set when the 50mA (RMS) current limiter is activated whether the current limiter is enabled or not. Transmit Open Circuit Detect. Set when the device detects that the TTIP and TRING outputs are open circuited. PRBS Detect. Set when the receive-side detects a 215-1 (E1) or a 220-1 (T1) Pseudo Random Bit Sequence (PRBS). 35 of 73 DS2148/DS21Q48 IMR (07H): INTERRUPT MASK REGISTER (MSB) LUP LDN LOTC SYMBOL POSITION LUP IMR.7 LDN IMR.6 LOTC IMR.5 RUA1 IMR.4 RCL IMR.3 TCLE IMR.2 TOCD IMR.1 PRBSD IMR.0 RUA1 RCL TCLE DESCRIPTION Loop Up Code Detected. 0 = interrupt masked 1 = interrupt enabled Loop Down Code Detected. 0 = interrupt masked 1 = interrupt enabled Loss of Transmit Clock. 0 = interrupt masked 1 = interrupt enabled Receive Unframed All Ones. 0 = interrupt masked 1 = interrupt enabled Receive Carrier Loss. 0 = interrupt masked 1 = interrupt enabled Transmit Current Limiter Exceeded. 0 = interrupt masked 1 = interrupt enabled Transmit Open Circuit Detect. 0 = interrupt masked 1 = interrupt enabled PRBS Detection. 0 = interrupt masked 1 = interrupt enabled 36 of 73 TOCD (LSB) PRBSD DS2148/DS21Q48 RIR1 (08H): RECEIVE INFORMATION REGISTER 1 (MSB) ZD 16ZD HBD RCLC RUA1C JALT N/A (LSB) N/A SYMBOL POSITION DESCRIPTION ZD (latched) RIR1.7 16ZD (latched) RIR1.6 HBD (latched) RIR1.5 RCLC (latched) RIR1.4 RUA1C (latched) RIR1.3 JALT (latched) RIR1.2 N/A RIR1.1 Zero Detect. Set when a string of at least four (ETS = 0) or eight (ETS = 1) consecutive zeros (regardless of the length of the string) have been received. Will be cleared when read. Sixteen Zero Detect. Set when at least 16 consecutive zeros (regardless of the length of the string) have been received. Will be cleared when read. HDB3/B8ZS Word Detect. Set when an HDB3 (ETS = 0) or B8ZS (ETS = 1) code word is detected independent of whether the receive HDB3/B8ZS mode (CCR4.6) is enabled. Will be cleared when read. Useful for automatically setting the line coding. Receive Carrier Loss Clear. Set when the RCL alarm has met the clear criteria defined in Error! Reference source not found.. Will be cleared when read. Receive Unframed All Ones Clear. Set when the unframed all ones signal is no longer detected. Will be cleared when read. See Error! Reference source not found.. Jitter Attenuator Limit Trip. Set when the jitter attenuator FIFO reaches to within 4 bits of its useful limit. Will be cleared when read. Useful for debugging jitter attenuation operation. Not Assigned. Could be any value when read. N/A RIR1.0 Not Assigned. Could be any value when read. 37 of 73 DS2148/DS21Q48 RIR2 (09H): RECEIVE INFORMATION REGISTER 2 (MSB) RL3 RL2 RL1 RL0 N/A N/A ARLB (LSB) SEC SYMBOL POSITION RL3 (real time) RL2 (real time) RL1 (real time) RL0 (real time) N/A N/A ARLB (real time) RIR2.7 Receive Level Bit 3. See Table 5-2. RIR2.6 Receive Level Bit 2. See Table 5-2. RIR2.5 Receive Level Bit 1. See Table 5-2. RIR2.4 Receive Level Bit 0. See Table 5-2. RIR2.3 RIR2.2 RIR2.1 Not Assigned. Could be any value when read. Not Assigned. Could be any value when read. Automatic Remote Loopback Detected. This bit will be set to a one when the automatic Remote Loopback (RLB) circuitry has detected the presence of a loop up code for 5 seconds. It will remain set until the automatic RLB circuitry has detected the loop down code for 5 seconds. See Section 4 for more details. This bit will be forced low when the automatic RLB circuitry is disabled (CCR6.5 = 0). One-Second Timer. This bit will be set to a one on one-second boundaries as timed by the device based on the RCLK. It will be cleared when read. SEC (latched) DESCRIPTION RIR2.0 Table 5-2. Receive Level Indication RL3 RL2 RL1 RL0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 RECEIVE LEVEL (dB) < -2.5 -2.5 to -5.0 -5.0 to -7.5 -7.5 to -10.0 -10.0 to -12.5 -12.5 to -15.0 -15.0 to -17.5 -17.5 to -20.0 -20.0 to -22.5 -22.5 to -25.0 -25.0 to -27.5 -27.5 to -30.0 -30.0 to -32.5 -32.5 to -35.0 -35.0 to -37.5 > -37.5 38 of 73 DS2148/DS21Q48 6 DIAGNOSTICS 6.1 In-Band Loop Code Generation and Detection The DS2148 can generate and detect a repeating bit pattern that is from one to eight or sixteen bits in length. To transmit a pattern, the user will load the pattern to be sent into the Transmit Code Definition (TCD1 and TCD2) registers and select the proper length of the pattern by setting the TC0 and TC1 bits in the In-Band Code Control (IBCC) register. When generating a 1, 2, 4, 8, or 16 bit pattern both the transmit code registers (TCD1 and TCD2) must be filled with the proper code. Generation of a 1, 3, 5, or 7-bit pattern only requires TCD1 to be filled. Once this is accomplished, the pattern will be transmitted as long as the TLCE control bit (CCR3.3) is enabled. As an example, if the user wished to transmit the standard “loop up” code for Channel Service Units which is a repeating pattern of ...10000100001... then 80h would be loaded into TCD1 and the length would set using TC1 and TC0 in the IBCC register to 5 bits. The DS2148 can detect two separate repeating patterns to allow for both a loop-up code and a loop-down code to be detected. The user will program the codes to be detected in the Receive Up Code Definition (RUPCD1 and RUPCD2) registers and the Receive Down Code Definition (RDNCD1 and RDNCD2) registers and the length of each pattern will be selected via the IBCC register. The DS2148 will detect repeating pattern codes with bit error rates as high as 1x10-2. The code detector has a nominal integration period of 48ms, hence, after about 48ms of receiving either code, the proper status bit (LUP at SR.7 and LDN at SR.6) will be set to a one. Normally codes are sent for a period of 5 seconds. It is recommended that the software poll the DS2148 every 100ms to 1000ms until 5 seconds has elapsed to ensure that the code is continuously present. IBCC (0AH): IN–BAND CODE CONTROL REGISTER (MSB) TC1 TC0 RUP2 RUP1 RUP0 RDN2 RDN1 (LSB) RDN0 SYMBOL POSITION DESCRIPTION TC1 IBCC.7 Transmit Code Length Definition Bit 1. See Table 6-1. TC0 IBCC.6 Transmit Code Length Definition Bit 0. See Table 6-1. RUP2 IBCC.5 Receive Up Code Length Definition Bit 2. See Table 6-2. RUP1 IBCC.4 Receive Up Code Length Definition Bit 1. See Table 6-2. RUP0 IBCC.3 Receive Up Code Length Definition Bit 0. See Table 6-2. RDN2 IBCC.2 Receive Down Code Length Definition Bit 2. See Table 6-2. RDN1 IBCC.1 Receive Down Code Length Definition Bit 1. See Table 6-2. RDN0 IBCC.0 Receive Down Code Length Definition Bit 0. See Table 6-2. 39 of 73 DS2148/DS21Q48 Table 6-1. Transmit Code Length TC1 TC0 0 0 1 1 0 1 0 1 LENGTH SELECTED (BITS) 5 6/3 7 16/8/4/2/1 Table 6-2. Receive Code Length RUP2/RDN2 RUP1/RDN1 RUP0/RDN0 0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1 LENGTH SELECTED (BITS) 1 2 3 4 5 6 7 16/8 TCD1 (0BH): TRANSMIT CODE DEFINITION REGISTER 1 (MSB) C7 C6 C5 C4 C3 C2 C1 (LSB) C0 SYMBOL POSITION DESCRIPTION C7 TCD1.7 C6 TCD1.6 Transmit Code Definition Bit 7. First bit of the repeating pattern. Transmit Code Definition Bit 6. C5 TCD1.5 Transmit Code Definition Bit 5. C4 TCD1.4 Transmit Code Definition Bit 4. C3 TCD1.3 Transmit Code Definition Bit 3. C2 TCD1.2 C1 TCD1.1 C0 TCD1.0 Transmit Code Definition Bit 2. A Don’t Care if a 5-bit length is selected. Transmit Code Definition Bit 1. A Don’t Care if a 5 or 6 bit length is selected. Transmit Code Definition Bit 0. A Don’t Care if a 5, 6 or 7 bit length is selected. 40 of 73 DS2148/DS21Q48 TCD2 (0CH): TRANSMIT CODE DEFINITION REGISTER 2 (MSB) C15 C14 C13 C12 C11 C10 SYMBOL POSITION C15 TCD2.7 Transmit Code Definition Bit 15 C14 TCD2.6 Transmit Code Definition Bit 14 C13 TCD2.5 Transmit Code Definition Bit 13 C12 TCD2.4 Transmit Code Definition Bit 12 C11 TCD2.3 Transmit Code Definition Bit 11 C10 TCD2.2 Transmit Code Definition Bit 10 C9 TCD2.1 Transmit Code Definition Bit 9 C8 TCD2.0 Transmit Code Definition Bit 8 C9 (LSB) C8 DESCRIPTION RUPCD1 (0DH): RECEIVE UP CODE DEFINITION REGISTER 1 (MSB) C7 C6 C5 C4 C3 C2 C1 (LSB) C0 SYMBOL POSITION DESCRIPTION C7 RUPCD1.7 C6 RUPCD1.6 C5 RUPCD1.5 C4 RUPCD1.4 C3 RUPCD1.3 C2 RUPCD1.2 C1 RUPCD1.1 C0 RUPCD1.0 Receive Up Code Definition Bit 7. First bit of the repeating pattern. Receive Up Code Definition Bit 6. A Don’t Care if a 1-bit length is selected. Receive Up Code Definition Bit 5. A Don’t Care if a 1 or 2 bit length is selected. Receive Up Code Definition Bit 4. A Don’t Care if a 1 to 3 bit length is selected. Receive Up Code Definition Bit 3. A Don’t Care if a 1 to 4 bit length is selected. Receive Up Code Definition Bit 2. A Don’t Care if a 1 to 5 bit length is selected. Receive Up Code Definition Bit 1. A Don’t Care if a 1 to 6 bit length is selected. Receive Up Code Definition Bit 0. A Don’t Care if a 1 to 7 bit length is selected. 41 of 73 DS2148/DS21Q48 RUPCD2 (0EH): RECEIVE UP CODE DEFINITION REGISTER 2 (MSB) C15 C14 C13 C12 C11 C10 SYMBOL POSITION DESCRIPTION C15 RUPCD2.7 Receive Up Code Definition Bit 15 C14 RUPCD2.6 Receive Up Code Definition Bit 14 C13 RUPCD2.5 Receive Up Code Definition Bit 13 C12 RUPCD2.4 Receive Up Code Definition Bit 12 C11 RUPCD2.3 Receive Up Code Definition Bit 11 C10 RUPCD2.2 Receive Up Code Definition Bit 10 C9 RUPCD2.1 Receive Up Code Definition Bit 9 C8 RUPCD2.0 Receive Up Code Definition Bit 8 C9 (LSB) C8 RDNCD1 (0FH): RECEIVE DOWN CODE DEFINITION REGISTER 1 (MSB) C7 C6 C5 C4 C3 C2 C1 (LSB) C0 SYMBOL POSITION DESCRIPTION C7 RDNCD1.7 C6 RDNCD1.6 C5 RDNCD1.5 C4 RDNCD1.4 C3 RDNCD1.3 C2 RDNCD1.2 C1 RDNCD1.1 C0 RDNCD1.0 Receive Down Code Definition Bit 7. First bit of the repeating pattern. Receive Down Code Definition Bit 6. A Don’t Care if a 1-bit length is selected. Receive Down Code Definition Bit 5. A Don’t Care if a 1 or 2 bit length is selected. Receive Down Code Definition Bit 4. A Don’t Care if a 1 to 3 bit length is selected. Receive Down Code Definition Bit 3. A Don’t Care if a 1 to 4 bit length is selected. Receive Down Code Definition Bit 2. A Don’t Care if a 1 to 5 bit length is selected. Receive Down Code Definition Bit 1. A Don’t Care if a 1 to 6 bit length is selected. Receive Down Code Definition Bit 0. A Don’t Care if a 1 to 7 bit length is selected. 42 of 73 DS2148/DS21Q48 RDNCD2 (10H): RECEIVE DOWN CODE DEFINITION REGISTER 2 (MSB) C15 C14 C13 C12 C11 C10 SYMBOL POSITION DESCRIPTION C15 RDNCD2.7 Receive Down Code Definition Bit 15 C14 RDNCD2.6 Receive Down Code Definition Bit 14 C13 RDNCD2.5 Receive Down Code Definition Bit 13 C12 RDNCD2.4 Receive Down Code Definition Bit 12 C11 RDNCD2.3 Receive Down Code Definition Bit 11 C10 RDNCD2.2 Receive Down Code Definition Bit 10 C9 RDNCD2.1 Receive Down Code Definition Bit 9 C8 RDNCD2.0 Receive Down Code Definition Bit 8 C9 (LSB) C8 6.2 Loopbacks 6.2.1 Remote Loopback (RLB) When RLB (CCR6.6) is enabled, the DS2148 is placed into remote loopback. In this loopback, data from the clock/data recovery state machine will be looped back to the transmit path passing through the jitter attenuator if it is enabled. The data at the RPOS and RNEG pins will be valid while data presented at TPOS and TNEG will be ignored (Figure 1-1). If the Automatic Remote Loopback Enable (CCR6.5) is set to a one, the DS2148 will automatically go into remote loopback when it detects the loop up code programmed in the Receive Up Code Definition Registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds. When the DS2148 detects the loop down code programmed in the Receive Loop Down Code Definition registers (RDNCD1 and RDNCD2) for a minimum of 5 seconds, the DS2148 will come out of remote loopback. Setting ARLBE to a zero also can disable the ARLB. 6.2.2 Local Loopback (LLB) When LLB (CCR6.7) is set to a one, the DS2148 is placed into local loopback. In this loopback, data on the transmit-side will continue to be transmitted as normal. TCLK and TPOS/TNEG will pass through the jitter attenuator (if enabled) and be output at RCLK and RPOS/RNEG. Incoming data from the line at RTIP and RRING will be ignored. If Transmit Unframed All Ones (CCR3.7) is set to a one while in LLB, TTIP and TRING will transmit all ones while TCLK and TPOS/TNEG will be looped back to RCLK and RPOS/RNEG (Figure 1-1). 43 of 73 DS2148/DS21Q48 6.2.3 Analog Loopback (ALB) Setting ALB (CCR6.4) to a one puts the DS2148 in Analog Loopback. Signals at TTIP and TRING will be internally connected to RTIP and RRING. The incoming signals at RTIP and RRING will be ignored. The signals at TTIP and TRING will be transmitted as normal. (See Figure 1-1.) 6.2.4 Dual Loopback (DLB) Setting both CCR6.7 and CCR6.6 to a one, LLB and RLB respectively, puts the DS2148 into dual loopback operation. The TCLK and TPOS/TNEG signals will be looped back through the jitter attenuator (if enabled) and output at RCLK and RPOS/RNEG. Clock and data recovered from RTIP and RRING will be looped back to the transmit-side and output at TTIP and TRING. This mode of operation is not available when implementing hardware operation. (See Figure 1-1.) 6.3 PRBS Generation and Detection Setting TPRBSE (CCR3.4) = 1 enables the DS2148 to transmit a 215-1 (E1) or a 220-1 (T1) Pseudo Random Bit Sequence (PRBS) depending on the ETS bit setting in CCR1.7. The receive-side of the DS2148 will always search for these PRBS patterns independent of CCR3.4. The PRBS Bit Error Output (PBEO) will remain high until the receiver has synchronized to one of the two patterns (64 bits received without an error) at which time PBEO will go low and the PRBSD bit in the status register (SR) will be set. Once synchronized, any bit errors received will cause a positive going pulse at PBEO, synchronous with RCLK. This output can be used with external circuitry to keep track of bit error rates during the PRBS testing. Setting CCR6.0 (ECRS) = 1 will allow the PRBS errors to be accumulated in the 16-bit counter in registers ECR1 and ECR2. The PRBS synchronizer will remain in sync until it experiences 6 bit errors or more within a 64-bit span. Both PRBS patterns comply with the ITU-T O.151 specifications. 6.4 Error Counter Error Count Register 1 (ECR1) is the most significant word and ECR2 is the least significant word of a user-selectable 16-bit counter that records incoming errors including Bipolar Violations (BPV), Code Violations (CV), Excessive Zero violations (EXZ) and/or PRBS Errors. See Table 6-3 and Table 6-4 and Figure 1-2 for details. Table 6-3. Definition of Received Errors ERROR E1 OR T1 BPV E1/T1 CV E1 EXZ E1 EXZ T1 PRBS E1/T1 DEFINITION OF RECEIVED ERRORS Two consecutive marks with the same polarity. Will ignore BPVs due to HDB3 and B8ZS zero suppression when CCR2.3 = 0. Typically used with AMI coding (CCR2.3 = 1). ITU-T O.161. When HDB3 is enabled (CCR2.3 = 0) and the receiver detects two consecutive BPVs with the same polarity. ITU-T O.161. When four or more consecutive zeros are detected. When receiving AMI coded signals (CCR2.3 = 1), detection of 16 or more zeros or a BPV. ANSI T1.403 1999. When receiving B8ZS coded signals (CCR2.3 = 0), detection of 8 or more zeros or a BPV. ANSI T1.403 1999. A bit error in a received PRBS pattern. See Section 6.3 for details. ITU-T O.151. 44 of 73 DS2148/DS21Q48 Table 6-4. Function of ECRS Bits and RNEG Pin E1 or T1 (CCR1.7) 0 0 0 0 1 1 1 1 X ECRS2 (CCR6.2) 0 0 0 0 0 0 0 0 1 ECRS1 (CCR6.1) 0 0 1 1 X X X X X ECRS0 (CCR6.0) 0 1 0 1 0 1 0 1 X RHBE (CCR2.3) X X X X 0 0 1 1 X FUNCTION OF ECR COUNTERS/RNEG1 CVs BPVs (HDB3 codewords not counted) CVs + EXZs BPVs + EXZs BPVs (B8ZS codewords not counted) BPVs + 8 EXZs BPVs BPVs + 16 EXZs PRBS Errors2 NOTES: 1) RNEG outputs error data only when in NRZ mode (CCR1.6 = 1). 2) PRBS errors will always be output at PBEO independent of ECR control bits and NRZ mode and will not be present at RNEG. 6.4.1 Error Counter Update A transition of the ECUE (CCR1.4) control bit from 0 to 1 will update the ECR registers with the current values and reset the counters. ECUE must be set back to zero and another 0 to 1 transition must occur for subsequent reads/resets of the ECR registers. Note that the DS2148 can report errors at RNEG when in NRZ mode (CCR1.6 = 1) by outputting a pulse for each error occurrence. The counter saturates at 65,535 and will not rollover. ECR1 (11H): UPPER ERROR COUNT REGISTER 1 ECR2 (12H): LOWER ERROR COUNT REGISTER 2 (MSB) E15 E7 E14 E6 E13 E5 SYMBOL POSITION E15 E0 ECR1.7 ECR2.0 E12 E4 E11 E3 E10 E2 E9 E1 (LSB) E8 E0 ECR1 ECR2 DESCRIPTION MSB of the 16-bit error count. LSB of the 16-bit error count. 6.5 Error Insertion When IBPV (CCR3.1) is transitioned from a zero to a one, the device waits for the next occurrence of three consecutive ones to insert a BPV. IBPV must be cleared and set again for another BPV error insertion. See Figure 1-3 for details on the insertion of the BPV into the datastream. When IBE (CCR3.0) is transitioned from a zero to a one, the device will insert a logic error. IBE must be cleared and set again for another logic error insertion. See Figure 1-3 for details on the insertion of the logic error into the datastream. 45 of 73 DS2148/DS21Q48 7 ANALOG INTERFACE 7.1 Receiver The DS2148 contains a digital clock recovery system. The DS2148 couples to the receive E1 or T1 twisted pair (or coaxial cable in 75Ω E1 applications) via a 1:1 transformer. See Table 7-3 or transformer details. Figure 7-1, Figure 7-2, and Figure 7-3 along with Table 7-1 and Table 7-2 show the receive termination requirements. The DS2148 has the option of using internal termination resistors. The DS2148 is designed to be fully software-selectable for E1 and T1 without the need to change any external resistors for the receive-side. The receive-side will allow the user to configure the DS2148 for 75Ω, 100Ω, or 120Ω receive termination by setting the RT1 (CCR5.1) and RT0 (CCR5.0) bits. When using the internal termination feature, the Rr resistors should be 60Ω each (Figure 7-1). If external termination is required, RT1 and RT0 should be set to 0 and both Rr resistors in Figure 7-1 will need to be 37.5Ω, 50Ω, or 60Ω each depending on the line impedance. The resultant E1 or T1 clock derived from the 2.048/1.544 PLL (JACLK in Figure 1-1) is internally multiplied by 16 via another internal PLL and fed to the clock recovery system. The clock recovery system uses the clock from the PLL circuit to form a 16 times oversampler, which is used to recover the clock and data. This oversampling technique offers outstanding performance to meet jitter tolerance specifications shown in Figure 7-6. Normally, the clock that is output at the RCLK pin is the recovered clock from the E1 AMI/HDB3 or T1 AMI/B8ZS waveform presented at the RTIP and RRING inputs. When no signal is present at RTIP and RRING, a Receive Carrier Loss (RCL) condition will occur and the RCLK will be derived from the JACLK source (Figure 1-1). If the jitter attenuator is placed in the receive path (as is the case in most applications), the jitter attenuator restores the RCLK to an approximate 50% duty cycle. If the jitter attenuator is either placed in the transmit path or is disabled, the RCLK output can exhibit slightly shorter high cycles of the clock. This is due to the highly oversampled digital clock recovery circuitry. See the Receive AC Timing Characteristics in Section 10 for more details. The receive-side circuitry also contains a clock synthesizer, which outputs a user configurable clock (up to 16.384MHz) synthesized to RCLK at BPCLK (pin 31). See Table 4-3 for details on output clock frequencies at BPCLK. In hardware mode, BPCLK defaults to a 16.384MHz output. The DS2148 has a bypass mode for the receive side clock and data. This allows the BPCLK to be derived from RCLK after the jitter attenuator while the clock and data presented at RCLK, RPOS, and RNEG go unaltered. This is intended for applications where the receive side jitter attenuation will be done after the LIU. Setting RJAB (CCR6.3) to a logic 1 will enable the bypass. Be sure that the jitter attenuator is in the receive path (CCR4.3 = 0). See Figure 1-1 for details. The DS2148 will report the signal strength at RTIP and RRING in 2.5dB increments via RL3-RL0 located in the Receive Information Register 2. This feature is helpful when trouble shooting line performance problems. See Table 5-2 for details. Monitor applications in both E1 and T1 require various flat gain settings for the receive-side circuitry. The DS2148 can be programmed to support these applications via the Monitor Mode control bits MM1 and MM0. When the monitor modes are enabled, the receiver will tolerate normal line loss up to –6dB. See Table 4-4 for details. 46 of 73 DS2148/DS21Q48 7.2 Transmitter The DS2148 uses a set of laser-trimmed delay lines along with a precision digital-to-analog converter (DAC) to create the waveforms that are transmitted onto the E1 or T1 line. The waveforms created by the DS2148 meet the latest ETSI, ITU, ANSI, and AT&T specifications. The user will select which waveform is to be generated by setting the ETS bit (CCR1.7) for E1 or T1 operation, then programming the L2/L1/L0 bits in Common Control Register 4 for the appropriate application. See Table 7-1 and Table 7-2 for the proper L2/L1/L0 settings. A 2.048MHz or 1.544MHz TTL clock is required at TCLK for transmitting data at TPOS and TNEG. ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. The clock can be sourced internally by RCLK or JACLK. See CCR1.2, CCR1.1, CCR1.0, and Figure 1-3 for details. Because of the nature of the DS2148 transmitter design, very little jitter (less than 0.005UIP-P broadband from 10Hz to 100kHz) is added to the jitter present on TCLK. Also, the waveforms created are independent of the duty cycle of TCLK. The transmitter in the DS2148 couples to the E1 or T1 transmit twisted pair (or coaxial cable in some E1 applications) via a 1:1.36 step-up transformer. In order for the device to create the proper waveforms, the transformer used must meet the specifications listed in Table 7-3. The DS2148 has automatic short-circuit limiter that limits the source current to 50mA (RMS) into a 1Ω load. This feature can be disabled by setting the SCLD bit (CCR2.5) = 1. When the current limiter is activated, TCLE (SR.2) will be set even if short circuit limiter is disabled. The TPD bit (CCR4.0) will power-down the transmit line driver and tri-state the TTIP and TRING pins. The DS2148 also can detect when the TTIP or TRING outputs are open-circuited. When an open circuit is detected, TOCD (SR.1) will be set. 7.3 Jitter Attenuator The DS2148 contains an on-board jitter attenuator that can be set to a depth of either 32 bits or 128 bits via the JABDS bit (CCR4.2). In hardware mode the depth is 128 bits and cannot be changed. The 128-bit mode is used in applications where large excursions of wander are expected. The 32-bit mode is used in delay sensitive applications. The characteristics of the attenuation are shown in Figure 7-7. The jitter attenuator can be placed in either the receive path or the transmit path by appropriately setting or clearing the JAS bit (CCR4.3). Also, the jitter attenuator can be disabled (in effect, removed) by setting the DJA bit (CCR4.1). In order for the jitter attenuator to operate properly, a 2.048MHz or 1.544MHz clock must be applied at MCLK. ITU specification G.703 requires an accuracy of ±50ppm for both T1 and E1. TR62411 and ANSI specs require an accuracy of ±32ppm for T1 interfaces. There is an onboard PLL for the jitter attenuator, which will convert the 2.048MHz clock to a 1.544MHz rate for T1 applications. Setting JAMUX (CCR1.3) to a logic 0 bypasses this PLL. On-board circuitry adjusts either the recovered clock from the clock/data recovery block or the clock applied at the TCLK pin to create a smooth jitterfree clock that is used to clock data out of the jitter attenuator FIFO. It is acceptable to provide a gapped/bursty clock at the TCLK pin if the jitter attenuator is placed on the transmit side. If the incoming jitter exceeds either 120UIP-P (buffer depth is 128 bits) or 28UIP-P (buffer depth is 32 bits), then the DS2148 will divide the internal nominal 32.768MHz (E1) or 24.704MHz (T1) clock by either 15 or 17 instead of the normal 16 to keep the buffer from overflowing. When the device divides by either 15 or 17, it also sets the jitter attenuator limit trip (JALT) bit in the receive information register 1 (RIR1). 47 of 73 DS2148/DS21Q48 7.4 G.703 Synchronization Signal The DS2148 is capable of receiving a 2.048MHz square-wave synchronization clock as specified in Section 13 of ITU G.703 (10/98). To use the DS2148 in this mode, set the receive synchronization clock enable (CCR5.3) = 1. The DS2148 can also transmit the 2.048MHz square-wave synchronization clock as specified in Section 10 of G.703. To transmit the 2.048MHz clock, set the transmit synchronization clock enable (CCR5.2) = 1. Table 7-1. Line Build-Out Select for E1 in Register CCR4 (ETS = 0) L2 0 0 1 1 L1 0 0 0 0 L0 0 1 0 1 VDD 5V 5V 5V 5V APPLICATION 75Ω normal 120Ω normal 75Ω w/ high return loss 120Ω w/ high return loss N 1:1.36 1:1.36 1:1.36 1:1.36 RETURN LOSS N.M. N.M. 21dB 21dB Rt 0Ω 0Ω 18Ω 27Ω N.M. = Not meaningful Note: See Figure 7-1, Figure 7-2, and Figure 7-3. Table 7-2. Line Build-Out Select for T1 in Register CCR4 (ETS = 1) L2 L1 L0 VDD 0 0 0 5V 0 0 0 1 1 1 1 0 1 1 0 0 1 1 1 0 1 0 1 0 1 5V 5V 5V 5V 5V 5V 5V APPLICATION DSX-1 (0 to 133 feet) / 0dB CSU DSX-1 (133 to 266 feet) DSX-1 (266 to 399 feet) DSX-1 (399 to 533 feet) DSX-1 (533 to 655 feet) -7.5dB CSU -15dB CSU -22.5dB CSU N RETURN LOSS Rt 1:1.36 N.M. 0Ω 1:1.36 1:1.36 1:1.36 1:1.36 1:1.36 1:1.36 1:1.36 N.M. N.M. N.M. N.M. N.M. N.M. N.M. 0Ω 0Ω 0Ω 0Ω 0Ω 0Ω 0Ω N.M. = Not meaningful Note: See Figure 7-1, Figure 7-2, and Figure 7-3.. Table 7-3. Transformer Specifications for 5V Operation SPECIFICATION Turns Ratio 5V Applications Primary Inductance Leakage Inductance Interwinding Capacitance Transmit Transformer DC Resistance Primary (Device Side) Secondary Receive Transformer DC Resistance Primary (Device Side) Secondary RECOMMENDED VALUE 1:1(receive) and 1:1.36(transmit) ±2% 600µH minimum 1.0µH maximum 40pF maximum 1.2Ω maximum 1.2Ω maximum 1.2Ω maximum 1.2Ω maximum 48 of 73 DS2148/DS21Q48 Figure 7-1. Basic Interface DS2148 Rt Transmit Line TTIP 0.47µF (non polarized) VDD (21) VSS (22) TRING Rt N:1 (larger winding toward the network) VDD (36) VSS (35) RTIP Receive Line RRING MCLK +VDD 0.1µF 0.01µF 10µF 0.1µF 10µF 2.048MHz (this clock can also be 1.544MHz for T1 only applications) 1:1 Rr Rr 0.1µF NOTES: 1) All resistor values are ±1%. 2) In E1 applications, the Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications. 3) The Rr resistors should be set to 60Ω each if the internal receive-side termination feature is enabled. When this feature is disabled, Rr = 37.5Ω for 75Ω, 60Ω for 120Ω E1 systems, or 50Ω for 100Ω T1 lines. 4) See Table 7-1 and Table 7-2 for the appropriate transmit transformer turns ratio (N). 49 of 73 DS2148/DS21Q48 Figure 7-2. Protected Interface Using Internal Receive Termination +VDD D1 (optional) Rp Fuse Rt Transmit Line Fuse TTIP 0.47uF (nonpolarized) S C1 TRING Rt Rp D3 N:1 (larger winding toward the network) DS2148 D2 D4 VDD (21) VSS (22) VDD (36) VSS (35) +VDD 0.1uF 0.01uF 10uF 68uF 0.1uF 10uF +VDD D6 D5 Fuse Rp RTIP Receive Line S Fuse Rp (optional) C2 RRING MCLK 2.048MHz (this clock can also be 1.544MHz for T1 only applications) 1:1 60 60 D7 D8 0.1uF NOTES: 1) All resistor values are ±1%. 2) C1 = C2 = 0.1µF. 3) S is a 6V transient suppresser. 4) D1 to D8 are Schottky diodes. 5) The fuses are optional to prevent AC power line crosses from compromising the transformers. 6) Rp resistors exist to keep the Fuses from opening during a surge. If they are used, then the 60Ω receive termination resistance must be adjusted to match the line impedance. 7) The Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications. 8) The transmit transformer turns ratio (N) would be 1:1.36 for 5V operation. 9) The 68µF is used to keep the local power plane potential within tolerance during a surge. 50 of 73 DS2148/DS21Q48 Figure 7-3. Protected Interface Using External Receive Termination +VDD D1 (optional) Rp Fuse Rt Transmit Line Fuse TTIP 0.47µF (nonpolarized) S D3 N:1 (larger winding toward the network) Fuse Rp Fuse Rp C1 TRING Rt Rp D4 470 RTIP Receive Line (optional) RRING 470 1:1 Rr DS2148 D2 VDD (21) VSS (22) VDD (36) VSS (35) MCLK +VDD 0.1µF 0.01µF 10µF 68µF 0.1µF 10µF 2.048MHz (this clock can also be 1.544MHz for T1 only applications) Rr 0.1µF NOTES: 1) All resistor values are ±1%. 2) C1 = 0.1µF. 3) S is a 6V transient suppresser. 4) D1 to D4 are Schottky diodes. 5) The fuses are optional to prevent AC power line crosses from compromising the transformers. 6) Rp resistors exist to keep the Fuses from opening during a surge. If they are used, then Rr must be adjusted to match the line impedance. 7) Rr = 37.5Ω for 75Ω, 60Ω for 120Ω E1 systems, or 50Ω for 100Ω T1 lines. 8) The Rt resistors are used to increase the transmitter return loss (Table 7-1). No return loss is required for T1 applications. 9) The transmit transformer turns ratio (N) would be 1:1.36 for 5V operation. 10) The 68µF is used to keep the local power plane potential within tolerance during a surge. 51 of 73 DS2148/DS21Q48 Figure 7-4. E1 Transmit Pulse Template 1.2 1.1 269ns SCALED AMPLITUDE (in 75 ohm systems, 1.0 on the scale = 2.37Vpeak in 120 ohm systems, 1.0 on the scale = 3.00Vpeak) 1.0 0.9 0.8 0.7 G.703 Template 194ns 0.6 0.5 219ns 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -250 -200 -150 -100 -50 0 TIME (ns) 52 of 73 50 100 150 200 250 DS2148/DS21Q48 Figure 7-5. T1 Transmit Pulse Template 1.2 MAXIMUM CURVE UI Time Amp. 1.1 1.0 -0.77 -0.39 -0.27 -0.27 -0.12 0.00 0.27 0.35 0.93 1.16 0.9 0.8 NORMALIZED AMPLITUDE 0.7 0.6 -500 -255 -175 -175 -75 0 175 225 600 750 0.05 0.05 0.80 1.15 1.15 1.05 1.05 -0.07 0.05 0.05 0.5 MINIMUM CURVE UI Time Amp. -0.77 -0.23 -0.23 -0.15 0.00 0.15 0.23 0.23 0.46 0.66 0.93 1.16 -500 -150 -150 -100 0 100 150 150 300 430 600 750 -0.05 -0.05 0.50 0.95 0.95 0.90 0.50 -0.45 -0.45 -0.20 -0.05 -0.05 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 T1.102/87, T1.403, CB 119 (Oct. 79), & I.431 Template -0.4 -0.5 -500 -400 -300 -200 -100 0 100 200 TIME (ns) 53 of 73 300 400 500 600 700 DS2148/DS21Q48 Figure 7-6. Jitter Tolerance UNIT INTERVALS (UIpp) 1K 100 DS2148 Tolerance TR 62411 (Dec. 90) 10 ITU-T G.823 1 0.1 1 10 100 1K FREQUENCY (Hz) 10K 100K Figure 7-7. Jitter Attenuation ITU G.7XX Prohibited Area TBR12 Prohibited Area -20dB C ve ur A E1 T1 TR 62411 (Dec. 90) Prohibited Area -40dB Cu B rve JITTER ATTENUATION (dB) 0dB -60dB 1 10 100 1K FREQUENCY (Hz) 54 of 73 10K 100K DS2148/DS21Q48 8 DS21Q48 QUAD LIU The DS21Q48 is a quad version of the DS2148G utilizing CSBGA on carrier packaging technology. The four LIUs are controlled via the parallel port mode. Serial and hardware modes are unavailable in this package. Table 8-1. DS21Q48 Pin Assignment DS21Q48 PIN# J1 K3 J2 H1 K2 K1 L1 H11 H12 G12 J10 H10 G11 J9 E3 D4 F3 D5 G4 K9 K7 L9 J6 L7 M8 M12 J3 D3 D10 K10 K5 G3 E10 K8 L6 D7 F9 I/O I I I I I I/O I I I I I/O I/O I/O I/O I/O I/O I/O I/O I I/O I I I I I I I I I I O O O O O O O PARALLEL PORT MODE Connect to VSS Connect to VSS RD(DS) WR(R/W) ALE(AS) A4 A3 A2 A1 A0 D7/AD7 D6/AD6 D5/AD5 D4/AD4 D3/AD3 D2/AD2 D1/AD1 D0/AD0 VSM INT TEST HRST MCLK BIS0 BIS1 PBTS CS1 CS2 CS3 CS4 PBEO1 PBEO2 PBEO3 PBEO4 RCL/LOTC1 RCL/LOTC2 RCL/LOTC3 55 of 73 DS2148/DS21Q48 DS21Q48 PIN# J7 A1 A4 A7 A10 B2 B5 B8 B11 H4 D6 F10 L8 A2 A5 A8 A11 B3 B6 B9 B12 K4 E1 D11 K11 G2 E2 F11 M10 H3 F1 E11 L11 G1 F2 E12 M11 H2 M1 D12 K12 M2 L2 F12 I/O O I I I I I I I I O O O O O O O O O O O O O O O O O O O O O O O O I I I I I I I I I I I PARALLEL PORT MODE RCL/LOTC4 RTIP1 RTIP2 RTIP3 RTIP4 RRING1 RRING2 RRING3 RRING4 BPCLK1 BPCLK2 BPCLK3 BPCLK4 TTIP1 TTIP2 TTIP3 TTIP4 TRING1 TRING2 TRING3 TRING4 RPOS1 RPOS2 RPOS3 RPOS4 RNEG1 RNEG2 RNEG3 RNEG4 RCLK1 RCLK2 RCLK3 RCLK4 TPOS1 TPOS2 TPOS3 TPOS4 TNEG1 TNEG2 TNEG3 TNEG4 TCLK1 TCLK2 TCLK3 56 of 73 DS2148/DS21Q48 DS21Q48 PIN# L12 J5 D2 G9 M9 L5 E4 D8 J8 J4 D1 E9 L10 M4 F4 D9 H9 I/O I - PARALLEL PORT MODE TCLK4 VDD1 VDD2 VDD3 VDD4 VDD1 VDD2 VDD3 VDD4 VSS1 VSS2 VSS3 VSS4 VSS1 VSS2 VSS3 VSS4 57 of 73 DS2148/DS21Q48 Figure 8-1. 144-Pin CSBGA (17mm x 17mm) Pinout 1 2 3 4 5 6 7 8 9 10 11 12 A RTIP 1 TTIP 1 NC RTIP 2 TTIP 2 NC RTIP 3 TTIP 3 NC RTIP 4 TTIP 4 NC B NC C NC NC NC NC NC D VSS 2 VDD 2 CS2 D2/ AD2 D0/ AD0 E RPOS 2 RNEG 2 D3/ AD3 VDD 2 NC NC F RCLK 2 TPOS 2 D1/ AD1 VSS 2 NC G TPOS 1 RNEG 1 PEBO 2 VSM H WR (R/W) TNEG 1 RCLK BPCLK 1 1 J See Note 2 RD (DS) K A4 ALE (AS) L A3 TCLK 2 NC M TNEG 2 TCLK 1 NC RRING TRING 1 1 CS1 NC RRING TRING 2 2 NC RRING TRING 4 4 NC NC NC NC VDD 3 VSS 3 CS3 RPOS 3 TNEG 3 NC NC VSS 3 PEBO 3 RCLK 3 TPOS 3 NC NC NC RCL/ BPCLK RNEG LOTC3 3 3 TCLK 3 NC NC NC NC VDD 3 NC D5/ AD5 A0 NC NC NC NC VSS 4 D6/ AD6 A2 A1 VDD 1 MCLK RCL/ LOTC4 VDD 4 D4/ AD4 D7/ AD7 NC NC PEBO 1 NC TEST PEBO 4 INT CS4 RPOS 4 TNEG 4 NC VDD 1 RCL/ LOTC1 BIS0 BPCLK HRST 4 VSS 4 RCLK 4 TCLK 4 VSS 1 NC NC NC RNEG 4 TPOS 4 PBTS RPOS See 1 Note 2 NC RRING TRING 3 3 NC VSS 1 NC NC BPCLK RCL/ 2 LOTC2 NOTES: 1) Shaded areas are signals common to all four devices. 2) Connect to VSS. 58 of 73 BIS1 VDD 4 DS2148/DS21Q48 9 DC CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS* Voltage Range on Any Pin Relative to Ground……………………………………………..-1.0V to +6.0V Operating Temperature Range for DS2148TN……………………………………………..-40°C to +85°C Storage Temperature Range……………………………………………………………….-55°C to +125°C Soldering Temperature………………………………………….See IPC/JEDEC J-STD-020 Specification * This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect device reliability. Table 9-1. Recommended DC Operating Conditions (TA = -40°C to +85°C) PARAMETER Logic 1 Logic 0 Supply for 5V Operation SYMBOL VIH VIL VDD MIN 2.0 –0.3 4.75 TYP MAX 5.5 +0.8 5.25 UNITS V V V NOTES SYMBOL CIN COUT MIN TYP 5 7 MAX UNITS pF pF NOTES MIN –1.0 TYP MAX +1.0 1.0 NOTES 3 4 95 125 UNITS µA µA mA mA mA 5 1 Table 9-2. Capacitance (TA = +25°C) PARAMETER Input Capacitance Output Capacitance Table 9-3. DC Characteristics (VDD = 5.0V ±5%, TA = -40°C to +85°C.) PARAMETER SYMBOL Input Leakage IIL Output Leakage ILO Output Current (2.4V) IOH Output Current (0.4V) IOL Supply Current IDD –1.0 +4.0 - NOTES: 1) 2) 3) 4) 5) Applies to VDD. TCLK = MCLK = 2.048MHz. 0.0V < VIN < VDD. Applied to INT when tri-stated. Power dissipation with TTIP and TRING driving a 30Ω load, for an all-ones data density. 59 of 73 2, 5 DS2148/DS21Q48 9.1 THERMAL CHARACTERISTICS Table 9-4. Thermal Characteristics—DS21Q48 CSBGA Package PARAMETER Ambient Temperature Junction Temperature Theta-JA (θJA) in Still Air Theta-JC (θJC) in Still Air MIN -40ºC - TYP +24ºC/W +4.1ºC/W MAX +85ºC +125ºC - NOTES 1 2 3 NOTES: 1) The package is mounted on a four-layer JEDEC-standard test board. 2) Theta-JA (θJA) is the junction to ambient thermal resistance, when the package is mounted on a fourlayer JEDEC-standard test board. 3) While Theta-JC (θJC) is commonly used as the thermal parameter that provides a correlation between the junction temperature (Tj) and the average temperature on top center of four of the chip-scale BGA packages (TC), the proper term is Psi-JT. It is defined by: (TJ - TC) / overall package power The method of measurement of the thermal parameters is defined in EIA/JEDEC-standard document EIA-JESD51-2. Table 9-5. Theta-JA (θJA) vs. Airflow FORCED AIR (m/s) 0 1 2.5 THETA-JA (θJA) 24ºC/W 21ºC/W 19ºC/W 60 of 73 DS2148/DS21Q48 10 AC CHARACTERISTICS Table 10-1. AC Characteristics—Multiplexed Parallel Port (BIS1 = 0, BIS0 = 0) (VDD = 5.0V ±5%, TA = -40°C to +85°C.) (See Figure 10-1, Figure 10-2, and Figure 10-3.) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Cycle Time tCYC 200 ns Pulse Width, DS Low or RD PWEL 100 ns High Pulse Width, DS High or RD PWEH 100 ns Low Input Rise/Fall times tR, tF 20 ns R/W Hold Time tRWH 10 ns R/W Setup Time Before DS tRWS 50 ns High CS Setup Time Before DS, tCS 20 ns WR or RD Active CS Hold Time tCH 0 ns Read Data Hold Time tDHR 10 50 ns Write Data Hold Time tDHW 0 ns Muxed Address Valid to AS tASL 15 ns or ALE Fall Muxed Address Hold Time tAHL 10 ns Delay Time DS, WR or RD to tASD 20 ns AS or ALE Rise Pulse Width AS or ALE High PWASH 30 ns Delay Time, AS or ALE to tASED 10 ns DS, WR or RD Output Data Delay Time tDDR 20 80 ns From DS or RD Data Setup Time tDSW 50 ns 61 of 73 DS2148/DS21Q48 Figure 10-1. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) t CYC ALE WR* PWASH t ASD t ASD t ASED PWEH RD* t CH t CS PWEL CS* t ASL t DHR t DDR AD0-AD7 t AHL Figure 10-2. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 0) t CYC ALE RD* PWASH t ASD t ASED t ASD WR* PWEL PWEH t CH t CS CS* t ASL t DHW AD0-AD7 t AHL 62 of 73 t DSW DS2148/DS21Q48 Figure 10-3. Motorola Bus Timing (PBTS = 1, BIS1 = 0, BIS0 = 0) PWASH AS DS PWEH t ASED t ASD PWEL t CYC t RWS t RWH R/W* AD0-AD7 (read) t DDR t ASL t AHL t DHR t CH t CS CS* AD0-AD7 (write) t DSW t ASL t DHW t AHL 63 of 73 DS2148/DS21Q48 Table 10-2. AC Characteristics—Nonmultiplexed Parallel Port (BIS1 = 0, BIS0 = 1) (VDD = 5.0V ±5%, TA = -40°C to +85°C.) (See Figure 10-4, Figure 10-5, Figure 10-6, and Figure 10-7.) PARAMETER SYMBOL MIN TYP MAX UNITS NOTES Setup Time for A0 to A4, Valid t1 0 ns to CS Active Setup Time for CS Active to t2 0 ns Either RD, WR, or DS Active Delay Time From Either RD or t3 75 ns DS Active to Data Valid Hold Time From Either RD, t4 0 ns WR, or DS Inactive to CS Inactive Hold Time From CS Inactive to t5 5 20 ns Data Bus tri-state Wait Time From Either WR or t6 75 ns DS Active to Latch Data Data Setup Time To Either WR t7 10 ns or DS Inactive Data Hold Time From Either t8 10 ns WR or DS Inactive Address Hold From Either WR t9 10 ns or DS Inactive 64 of 73 DS2148/DS21Q48 Figure 10-4. Intel Bus Read Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) A0 to A4 Address Valid D0 to D7 Data Valid t5 5ns min. / 20ns max. WR* t1 0ns min. CS* 0ns min. t2 t3 75ns max. RD* t4 0ns min. Figure 10-5. Intel Bus Write Timing (PBTS = 0, BIS1 = 0, BIS0 = 1) A0 to A4 Address Valid D0 to D7 t7 10ns min. RD* t1 t8 10ns min. 0ns min. CS* 0ns min. WR* t2 t6 75ns min. 65 of 73 t4 0ns min. DS2148/DS21Q48 Figure 10-6. Motorola Bus Read Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) A0 to A4 Address Valid D0 to D7 Data Valid 5ns min. / 20ns max. t5 R/W* t1 0ns min. CS* 0ns min. t2 t3 t4 0ns min. 75ns max. DS* Figure 10-7. Motorola Bus Write Timing (PBTS = 1, BIS1 = 0, BIS0 = 1) A0 to A4 Address Valid D0 to D7 10ns min. R/W* t1 t7 t8 10ns min. 0ns min. CS* 0ns min. DS* t2 t6 75ns min. 66 of 73 t4 0ns min. DS2148/DS21Q48 Table 10-3. AC Characteristics—Serial Port (BIS1 = 1, BIS0 = 0) (VDD = 5.0V ±5%, TA = -40°C to +85°C.) (See Figure 10-8) PARAMETER SYMBOL MIN TYP Setup Time CS to SCLK tCSS 50 Setup Time SDI to SCLK tSSS 50 Hold Time SCLK to SDI tSSH 50 SCLK High/Low Time tSLH 200 SCLK Rise/Fall Time tSRF SCLK to CS Inactive tLSC 50 CS Inactive Time tCM 250 SCLK to SDO Valid tSSV SCLK to SDO Tri-state tSSH 100 CS Inactive to SDO Tri-state tCSH 100 MAX UNITS ns ns ns ns ns ns ns ns ns ns 50 50 Figure 10-8. Serial Bus Timing (BIS1 = 1, BIS0 = 0) tCM CS* tSRF tCSS tLSC tSLH SCLK1 SCLK2 SDI tSSS tSSH LSB tCSH MSB LSB MSB tSSV SDO HIGH Z LSB NOTE 1: OCES =1 AND ICES = 0. NOTE 2: OCES = 0 AND ICES = 1. 67 of 73 tSSH MSB HIGH Z NOTES DS2148/DS21Q48 Table 10-4. AC Characteristics—Receive Side (VDD = 5.0V ±5%, TA = -40°C to +85°C.) (See Figure 10-9) PARAMETER SYMBOL MIN TYP 488 RCLK Period tCP 648 tCH 200 RCLK Pulse Width 200 tCL tCH 150 RCLK Pulse Width tCL 150 Delay RCLK to RPOS, RNEG, tDD PBEO, RBPV Valid MAX UNITS ns ns ns ns ns ns 50 ns NOTES: 1) 2) 3) 4) E1 Mode. T1 or J1 Mode. Jitter attenuator enabled in the receive path. Jitter attenuator disabled or enabled in the transmit path. Figure 10-9. Receive Side Timing RCLK1 t CL RCLK2 t CH t CP t DD RPOS, RNEG PBEO bit error PRBS Detector Out of Sync t DD RNEG3 BPV/ EXZ/ CV BPV/ EXZ/ CV NOTE 1: RCES = 1 (CCR2.0) OR CES = 1. NOTE 2: RCES = 0 (CCR2.0) OR CES = 0. NOTE 3: RNEG IS IN NRZ MODE (CCR1.6 = 1). 68 of 73 NOTES 1 2 3 3 4 4 DS2148/DS21Q48 Table 10-5. AC Characteristics—Transmit Side (VDD = 5.0V ±5%, TA = -40°C to +85°C.) (See Figure 10-10.) PARAMETER SYMBOL MIN TYP 488 TCLK Period tCP 648 tCH 75 TCLK Pulse Width tCL 75 TPOS/TNEG Setup to TCLK tSU 20 Falling or Rising TPOS/TNEG Hold From TCLK tHD 20 Falling or Rising TCLK Rise and Fall Times tR, tF MAX ns ns 25 NOTES: 1) E1 Mode. 2) T1 or J1 Mode. Figure 10-10. Transmit Side Timing t CP tR t CL tF TCLK1 TCLK2 t SU TPOS, TNEG t HD NOTE 1: TCES = 0 (CCR2.1) OR CES = 0. NOTE 2: TCES = 1 (CCR2.1) OR CES = 1. 69 of 73 UNITS ns ns ns ns t CH ns NOTES 1 2 DS2148/DS21Q48 11 PACKAGE INFORMATION (The package drawing(s) in this data sheet may not reflect the most current specifications. The package number provided for each package is a link to the latest package outline information.) 11.1 44-Pin TQFP (56-G4012-001) SUGGESTED PAD LAYOUT 44 PIN TQFP, 10*10*1.0 SEE DETAIL "A" DIMENSIONS ARE IN MILLIMETERS 70 of 73 DS2148/DS21Q48 11.2 49-Ball CSGBA (7mm x 7mm) (56-G6006-001) 71 of 73 DS2148/DS21Q48 11.3 144-Ball CSBGA (17mm x 17mm) (56-G6011-001) A1 CORNER 3 A1 CORNER 12 11 10 9 8 7 6 5 4 3 2 1 A B C D E F G H I J K L 1.27 17.00 13.97 0.20 1.52 Y 4 17.00 1.27 X 13.97 1.52 DETAIL A TOP VIEW (DIE SIDE) BOTTOM VIEW (BALL SIDE) 0.05 2.60 REF 1.99 0.76 Z DETAIL B SIDE VIEW 72 of 73 0.61 0.59 DS2148/DS21Q48 SOLDER BALL φ 0.76 REF φ 0.76 L X φ 0.76 L Z Y Z DETAIL A 0.05 LABEL THICKNESS // 0.24 Z 2.60 REF // 0.17 Z 0.10 SEATING PLANE 2 0.76 REF Z DETAIL B 73 of 73 Maxim/Dallas Semiconductor cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim/Dallas Semiconductor product. No circuit patent licenses are implied. Maxim/Dallas Semiconductor reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2006 Maxim Integrated Products • Printed USA The Maxim logo is a registered trademark of Maxim Integrated Products, Inc. The Dallas logo is a registered trademark of Dallas Semiconductor Corporation.