CY7C1370B-150AC

CY7C1370B CY7C1372B 512K × 36/1M × 18 Pipelined SRAM with NoBL Architecture Features • Zero Bus Latency, no dead cycles between Write and Read cycles • Fast clock speed: 200, 167, 150, and 133 MHz • Fast access time: 3.0, 3.4, 3.8, and 4.2 ns • Internally synchronized registered outputs eliminate the need to control OE • Single 3.3V –5% and +10% power supply VDD • Separate VDDQ for 3.3V or 2.5V I/O • Single WE (Read/Write) control pin • Positive clock-edge triggered address, data, and control signal registers for fully pipelined applications • Interleaved or linear four-word burst capability • Individual byte Write (BWSa–BWSd) control (may be tied LOW) • CEN pin to enable clock and suspend operations • Three chip enables for simple depth expansion • JTAG boundary scan (BGA package only) • Available in 119-ball bump BGA and 100-pin TQFP packages • Automatic power down available using ZZ mode or CE deselect Functional Description The CY7C1370B and CY7C1372B SRAMs are designed to eliminate dead cycles when transitions from Read to Write or vice versa. These SRAMs are optimized for 100 percent bus utilization and achieve Zero Bus Latency™. They integrate 524,288 × 36 and 1,048,576 × 18 SRAM cells, respectively, with advanced synchronous peripheral circuitry and a 2-bit counter for internal burst operation. The Synchronous Burst SRAM family employs high-speed, low-power CMOS designs using advanced single-layer polysilicon, three-layer metal technology. Each memory cell consists of six transistors. All synchronous inputs are gated by registers controlled by a positive-edge-triggered Clock input (CLK). The synchronous inputs include all addresses, all data inputs, depth-expansion Chip Enables (CE1, CE2, and CE3), cycle start input (ADV/LD), Clock enable (CEN), byte Write Enables (BWSa, BWSb, BWSc, and BWSd), and Read-Write Control (WE). BWSc and BWSd apply to CY7C1370B only. Address and control signals are applied to the SRAM during one clock cycle, and two cycles later, its associated data occurs, either Read or Write. A Clock enable (CEN) pin allows operation of the CY7C1370B/CY7C1372B to be suspended as long as necessary. All synchronous inputs are ignored when CEN is HIGH and the internal device registers will hold their previous values. There are three chip enable pins (CE1, CE2, CE3) that allow the user to deselect the device when desired. If any one of these three are not active when ADV/LD is LOW, no new memory operation can be initiated and any burst cycle in progress is stopped. However, any pending data transfers (Read or Write) will be completed. The data bus will be in high-impedance state two cycles after the chip is deselected or a Write cycle is initiated. The CY7C1370B and CY7C1372B have an on-chip two-bit burst counter. In the burst mode, the CY7C1370B and CY7C1372B provide four cycles of data for a single address presented to the SRAM. The order of the burst sequence is defined by the MODE input pin. The MODE pin selects between linear and interleaved burst sequence. The ADV/LD signal is used to load a new external address (ADV/LD = LOW) or increment the internal burst counter (ADV/LD = HIGH) Output enable (OE) and burst sequence select (MODE) are the asynchronous signals. OE can be used to disable the outputs at any given time. ZZ may be tied to LOW if it is not used. Four pins are used to implement JTAG test capabilities. The JTAG circuitry is used to serially shift data to and from the device. JTAG inputs use LVTTL/LVCMOS levels to shift data during this testing mode of operation. Logic Block Diagram CLK CE D Data-In REG. Q Ax AX CY7C1370 CY7C1372 X = 18:0 X = 19:0 DQX X = a, b, c, d X = a, b DPX BWSX X = a, b, c, d X = a, b X = a, b, c, d X = a, b CEN CE1 CE2 CE3 WE BWSX CONTROL and Write LOGIC 256K × 36/ 512K × 18 MEMORY ARRAY OUTOUT REGISTERS and LOGIC ADV/LD DQX DPX Mode OE Cypress Semiconductor Corporation Document #: 38-05197 Rev. *C • 3901 North First Street • San Jose, CA 95134 • 408-943-2600 Revised January 18, 2003 CY7C1370B CY7C1372B . Selection Guide 200 MHz Maximum Access Time Maximum Operating Current Commercial Maximum CMOS Standby Current 167 MHz 150 MHz 133 MHz Unit 3.0 3.4 3.8 4.2 ns 315 285 265 245 mA 20 20 20 20 mA Pin Configurations CY7C1370B 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 DPb DQb DQb VDDQ VSS VDDQ VSS NC NC DQb DQb VSS VDDQ DQb DQb NC VDD NC VSS DQb DQb VDDQ VSS DQb DQb DPb NC VSS VDDQ NC NC NC 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 CY7C1372B (1M × 18) 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 Document #: 38-05197 Rev. *C A NC NC VDDQ VSS NC DPa DQa DQa VSS VDDQ DQa DQa VSS NC VDD ZZ DQa DQa VDDQ VSS DQa DQa NC NC VSS VDDQ NC NC NC DNU DNU A A A A A A A DNU DNU A A A A A A A 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 DQb DQb DQb DQb VSS VDDQ DQb DQb VSS NC VDD ZZ DQa DQa VDDQ VSS DQa DQa DQa DQa VSS VDDQ DQa DQa DPa NC NC NC MODE A A A A A1 A0 DNU DNU VSS VDD (512K × 36) 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 DQc DQc NC VDD NC VSS DQd DQd VDDQ VSS DQd DQd DQd DQd VSS VDDQ DQd DQd DPd 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 MODE A A A A A1 A0 DNU DNU VSS VDD DPc DQc DQc VDDQ VSS DQc DQc DQc DQc VSS VDDQ A A A A CE1 CE2 NC NC BWSb BWSa CE3 VDD VSS CLK WE CEN OE ADV/LD A A A A 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 A A CE1 CE2 BWSd BWSc BWSb BWSa CE3 VDD VSS CLK WE CEN OE ADV/LD A A 100-Pin TQFP Packages Page 2 of 27 CY7C1370B CY7C1372B Pin Configurations (continued) 119-ball Bump BGA CY7C1370B (512K × 36) – 7 × 17 BGA 1 2 3 4 5 6 7 A VDDQ A A A A A VDDQ B C D E F G H J K L M N P NC NC CE2 A A A ADV/LD VDD A A CE3 A NC NC DQc DPc VSS NC VSS DPb DQb DQc DQc VSS CE1 VSS DQb DQb VDDQ DQc VSS OE VSS DQb VDDQ R T U DQc DQc BWSc A BWSb DQb DQb DQc VDDQ DQc VDD VSS NC WE VDD VSS NC DQb VDD DQb VDDQ DQd DQd DQd DQd VSS BWSd CLK NC VSS BWSa DQa DQa DQa DQa VDDQ DQd VSS CEN VSS DQa VDDQ DQd DQd VSS A1 VSS DQa DQa DQd DPd VSS A0 VSS DPa DQa NC A MODE VDD NC A NC NC 64M A A A 32M ZZ VDDQ TMS TDI TCK TDO NC VDDQ CY7C1372B (1M × 18) – 7 × 17 BGA A B C D E F G H J K L M N P R T U Document #: 38-05197 Rev. *C 1 2 3 4 5 6 7 VDDQ A A A A A VDDQ NC CE2 A ADV/LD A CE3 NC NC A A VDD A A NC DQb NC VSS NC VSS DPa NC NC DQb VSS CE1 VSS NC DQa VDDQ NC VSS OE VSS DQa VDDQ NC DQb VDDQ DQb NC VDD BWSb VSS NC A WE VDD VSS VSS NC NC DQa VDD DQa NC VDDQ NC DQb VSS CLK VSS NC DQa DQb NC VSS NC BWSa DQa NC VDDQ DQb VSS CEN VSS NC VDDQ DQb NC VSS A1 VSS DQa NC NC DPb VSS A0 VSS NC DQa NC NC A MODE VDD NC A 64M A A 32M A A ZZ VDDQ TMS TDI TCK TDO NC VDDQ Page 3 of 27 CY7C1370B CY7C1372B Pin Configurations (continued) 165-ball Bump FBGA CY7C1370B (512K × 36) – 11 × 15 FBGA 1 2 3 4 5 6 7 8 9 10 11 A NC A CE1 BWSc BWSb CE3 CEN ADV/LD A A NC B C D E F G H J K L M N P NC DPc A NC CE2 VDDQ BWSd VSS BWSa VSS CLK VSS WE VSS OE VSS A VDDQ A NC 128M DPb DQb R DQc DQc VDDQ VDD VSS VSS VSS VDD VDDQ DQb DQc DQc VDDQ VDD VSS VSS VSS VDD VDDQ DQb DQb DQc DQc VDDQ VDD VSS VSS VSS VDD VDDQ DQb DQb DQc DQc VDDQ VDD VSS VSS VSS VDD VDDQ DQb DQb NC DQd VDD DQd NC VDDQ VDD VDD VSS VSS VSS VSS VSS VSS VDD VDD NC VDDQ NC DQa ZZ DQa DQd DQd DQd DQd VDDQ VDDQ VDD VDD VSS VSS VSS VSS VSS VSS VDD VDD VDDQ VDDQ DQa DQa DQa DQa DQd DQd VDDQ VDD VSS VSS VSS VDD VDDQ DQa DQa DPd NC VDDQ VSS NC NC NC VSS VDDQ NC DPa NC 64M A A TDI A1 TDO A A A NC MODE 32M A A TMS A0 TCK A A A A 11 CY7C1372B (1M × 18) – 11 × 15 FBGA 1 2 3 4 5 6 7 8 9 10 A NC A CE1 BWSb NC CE3 CEN ADV/LD A A A B C D E F G H J K L M N P NC NC A NC CE2 VDDQ NC VSS BWSa VSS CLK VSS WE VSS OE VSS A VDDQ A NC 128M DPa NC DQb VDDQ VDD VSS VSS VSS VDD VDDQ NC DQa NC DQb VDDQ VDD VSS VSS VSS VDD VDDQ NC DQa NC DQb VDDQ VDD VSS VSS VSS VDD VDDQ NC DQa NC DQb VDDQ VDD VSS VSS VSS VDD VDDQ NC DQa NC DQb VDD NC NC VDDQ VDD VDD VSS VSS VSS VSS VSS VSS VDD VDD NC VDDQ NC DQa ZZ NC DQb DQb NC NC VDDQ VDDQ VDD VDD VSS VSS VSS VSS VSS VSS VDD VDD VDDQ VDDQ DQa DQa NC NC DQb NC VDDQ VDD VSS VSS VSS VDD VDDQ DQa NC DPb NC VDDQ VSS NC NC NC VSS VDDQ NC NC NC 64M A A TDI A1 TDO A A A NC MODE 32M A A TMS A0 TCK A A A A R Document #: 38-05197 Rev. *C Page 4 of 27 CY7C1370B CY7C1372B Pin Definitions Name I/O Type Description A0 A1 A InputSynchronous Address inputs used to select one of the 524,288/1,048576 address locations. Sampled at the rising edge of the CLK. BWSa BWSb BWSc BWSd InputSynchronous Byte Write Select inputs, active LOW. Qualified with WE to conduct writes to the SRAM. Sampled on the rising edge of CLK. BWSa controls DQa and DPa, BWSb controls DQb and DPb, BWSc controls DQc and DPc, BWSd controls DQd and DPd. WE InputSynchronous Write enable input, active LOW. Sampled on the rising edge of CLK if CEN is active LOW. This signal must be asserted LOW to initiate a Write sequence. ADV/LD InputSynchronous Advance/Load input used to advance the on-chip address counter or load a new address. When HIGH (and CEN is asserted LOW) the internal burst counter is advanced. When LOW, a new address can be loaded into the device for an access. After being deselected, ADV/LD should be driven LOW in order to load a new address. CLK Input-Clock Clock input. Used to capture all synchronous inputs to the device. CLK is qualified with CEN. CLK is only recognized if CEN is active LOW. CE1 InputSynchronous Chip enable 1 input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with CE2 and CE3 to select/deselect the device. CE2 InputSynchronous Chip enable 2 input, active HIGH. Sampled on the rising edge of CLK. Used in conjunction with CE1 and CE3 to select/deselect the device. CE3 InputSynchronous Chip enable 3 input, active LOW. Sampled on the rising edge of CLK. Used in conjunction with CE1 and CE2 to select/deselect the device. OE InputAsynchronous Output enable, active LOW. Combined with the synchronous logic block inside the device to control the direction of the I/O pins. When LOW, the I/O pins are allowed to behave as outputs. When deasserted HIGH, I/O pins are three-stated, and act as input data pins. OE is masked during the data portion of a Write sequence, during the first clock when emerging from a deselected state and when the device has been deselected. CEN InputSynchronous Clock enable input, active LOW. When asserted LOW the clock signal is recognized by the SRAM. When deasserted HIGH the clock signal is masked. Since deasserting CEN does not deselect the device, CEN can be used to extend the previous cycle when required. DQa DQb DQc DQd I/OSynchronous Bidirectional Data I/O lines. As inputs, they feed into an on-chip data register that is triggered by the rising edge of CLK. As outputs, they deliver the data contained in the memory location specified by AX during the previous clock rise of the Read cycle. The direction of the pins is controlled by OE and the internal control logic. When OE is asserted LOW, the pins can behave as outputs. When HIGH, DQa–DQd are placed in a three-state condition. The outputs are automatically three-stated during the data portion of a Write sequence, during the first clock when emerging from a deselected state, and when the device is deselected, regardless of the state of OE.DQ a, b, c and d are eight-bits wide. DPa DPb DPc DPd I/OSynchronous Bidirectional Data Parity I/O lines. Functionally, these signals are identical to DQ[31:0]. During Write sequences, DPa is controlled by BWSa, DPb is controlled by BWSb, DPc is controlled by BWSc, and DPd is controlled by BWSd.DP a, b, c and d are one-bit wide ZZ InputAsynchronous ZZ “sleep” input. This active HIGH input places the device in a non-time critical “sleep” condition with data integrity preserved. Input Pin Mode input. Selects the burst order of the device. Tied HIGH selects the interleaved burst order. Pulled LOW selects the linear burst order. MODE should not change states during operation. When left floating MODE will default HIGH, to an interleaved burst order. MODE VDD Power Supply VDDQ I/O Power Supply TDO JTAG serial output Synchronous Document #: 38-05197 Rev. *C Power supply inputs to the core of the device. Power supply for the I/O circuitry. Serial data-out to the JTAG circuit. Delivers data on the negative edge of TCK (BGA only). Page 5 of 27 CY7C1370B CY7C1372B Pin Definitions Name I/O Type TDI JTAG serial input Synchronous TMS Test Mode Select Synchronous TCK JTAG serial clock 32M 64M 128M – Description Serial data-In to the JTAG circuit. Sampled on the rising edge of TCK.(BGA Only) This pin controls the Test Access Port (TAP) state machine. Sampled on the rising edge of TCK (BGA only). Serial clock to the JTAG circuit (BGA only). No connects. Reserved for address expansion. Pins are not internally connected. VSS Ground NC – No connects. Pins are not internally connected. DNU – Do not use pins. Document #: 38-05197 Rev. *C Ground for the device. Should be connected to ground of the system. Page 6 of 27 CY7C1370B CY7C1372B Introduction Functional Overview The CY7C1370B/CY7C1372B are synchronous-pipelined Burst NoBL™ SRAMs designed specifically to eliminate wait states during Write/Read transitions. All synchronous inputs pass through input registers controlled by the rising edge of the clock. The clock signal is qualified with the CEN input signal. If CEN is HIGH, the clock signal is not recognized and all internal states are maintained. All synchronous operations are qualified with CEN. All data outputs pass through output registers controlled by the rising edge of the clock. Maximum access delay from the clock rise (tCO) is 3.8 ns (150-MHz device). Accesses can be initiated by asserting all three Chip Enables (CE1, CE2, CE3) active at the rising edge of the clock. If the CEN is active LOW and ADV/LD is asserted LOW, the address presented to the device will be latched. The access can either be a Read or Write operation, depending on the status of the Write enable (WE). BWS[d:a] can be used to conduct byte Write operations. Write operations are qualified by the Write enable (WE). All writes are simplified with on-chip synchronous self-timed write circuitry. Three synchronous CE1, CE2, CE3 and an asynchronous OE simplify depth expansion. All operations (Reads, Writes, and Deselects) are pipelined. ADV/LD should be driven LOW once the device has been deselected in order to load a new address for the next operation. Single Read Accesses A Read access is initiated when the following conditions are satisfied at clock rise: (1) CEN is asserted LOW, (2) CE1, CE2, and CE3 are ALL asserted active, (3) the Write enable input signal WE is deasserted HIGH, and (4) ADV/LD is asserted LOW. The address presented to the address inputs is latched into the Address Register and presented to the memory core and control logic. The control logic determines that a Read access is in progress and allows the requested data to propagate to the input of the output register. At the rising edge of the next clock the requested data is allowed to propagate through the output register and onto the data bus within 3.8 ns (150-MHz device) provided OE is active LOW. After the first clock of the Read access the output buffers are controlled by OE and the internal control logic. OE must be driven LOW in order for the device to drive out the requested data. During the second clock, a subsequent operation (Read/Write/Deselect) can be initiated. Deselecting the device is also pipelined. Therefore, when the SRAM is deselected at clock rise by one of the chip enable signals, its output will three-state following the next clock rise. Burst Read Accesses The CY7C1370B/CY7C1372B have on-chip burst counters that allow the user the ability to supply a single address and conduct up to four Reads without reasserting the address inputs. ADV/LD must be driven LOW in order to load a new address into the SRAM, as described in the Single Read Access section above. The sequence of the burst counter is determined by the MODE input signal. A LOW input on MODE selects a linear burst mode, a HIGH selects an interleaved burst sequence. Both burst counters use A0 and A1 in the Document #: 38-05197 Rev. *C burst sequence, and will wrap-around when incremented sufficiently. A HIGH input on ADV/LD will increment the internal burst counter regardless of the state of chip enables inputs or WE. WE is latched at the beginning of a burst cycle. Therefore, the type of access (Read or Write) is maintained throughout the burst sequence. Single Write Accesses Write access are initiated when the following conditions are satisfied at clock rise: (1) CEN is asserted LOW, (2) CE1, CE2, and CE3 are ALL asserted active, and (3) the Write signal WE is asserted LOW. The address presented to Ax is loaded into the Address Register. The Write signals are latched into the Control Logic block. On the subsequent clock rise the data lines are automatically three-stated regardless of the state of the OE input signal. This allows the external logic to present the data on DQ and DQP (DQa,b,c,d/DPa,b,c,d for CY7C1370B and DQa,b/DPa,b for CY7C1372B). In addition, the address for the subsequent access (Read/Write/Deselect) is latched into the Address Register (provided that the appropriate control signals are asserted). On the next clock rise the data presented to DQ and DP (DQa,b,c,d/DPa,b,c,d for CY7C1370B and DQa,b/DPa,b for CY7C1372B) (or a subset for byte Write operations, see Write Cycle Description table for details) inputs is latched into the device and the Write is complete. The data written during the Write operation is controlled by BWS (BWSa,b,c,d for CY7C1370B and BWSa,b for CY7C1372B) signals. The CY7C1370B/CY7C1372B provides byte Write capability that is described in the Write Cycle Description table. Asserting the Write enable input (WE) with the selected Byte Write Select (BWS) input will selectively write to only the desired bytes. Bytes not selected during a byte Write operation will remain unaltered. A synchronous self-timed Write mechanism has been provided to simplify Write operations. Byte Write capability has been included in order to greatly simplify Read/Modify/Write sequences, which can be reduced to simple byte Write operations. Because the CY7C1370B/CY7C1372B is a common I/O device, data should not be driven into the device while the outputs are active. The OE can be deasserted HIGH before presenting data to the DQ and DP (DQa,b,c,d/DPa,b,c,d for CY7C1370B and DQa,b/DPa,b for CY7C1372B) inputs. Doing so will three-state the output drivers. As a safety precaution, DQ and DP (DQa,b,c,d/DPa,b,c,d for CY7C1370B and DQa,b/DPa,b for CY7C1372B) are automatically three-stated during the data portion of a Write cycle, regardless of the state of OE. Burst Write Accesses The CY7C1370B/CY7C1372B has an on-chip burst counter that allows the user the ability to supply a single address and conduct up to four Write operations without reasserting the address inputs. ADV/LD must be driven LOW in order to load the initial address, as described in the Single Write Access section above. When ADV/LD is driven HIGH on the subsequent clock rise, the chip enables (CE1, CE2, and CE3) and WE inputs are ignored and the burst counter is incremented. The correct BWS (BWSa,b,c,d for CY7C1370B and BWSa,b for CY7C1372B) inputs must be driven in each cycle of the burst Write in order to write the correct bytes of data. Page 7 of 27 CY7C1370B CY7C1372B Cycle Description Truth Table[1, 2, 3, 4, 5, 6] Address Used CE CEN ADV/ LD/ WE BWSX CLK External 1 0 L X X L–H I/Os three-state following next recognized clock. – X 1 X X X L–H Clock ignored, all operations suspended. Begin Read External 0 0 0 1 X L–H Address latched. Begin Write External 0 0 0 0 Valid L–H Address latched, data presented two valid clocks later. Burst Read Operation Internal X 0 1 X X L–H Burst Read operation. Previous access was a Read operation. Addresses incremented internally in conjunction with the state of Mode. Burst Write Operation Internal X 0 1 X Valid L–H Burst Write operation. Previous access was a Write operation. Addresses incremented internally in conjunction with the state of MODE. Bytes written are determined by BWS[d:a]. Operation Deselected Suspend Interleaved Burst Sequence First Address Second Address Third Address Comments Linear Burst Sequence Fourth Address First Address Second Address Third Address Fourth Address A[1:0] A[1:0] A[1:0] A[1:0] A[1:0] A[1:0] A[1:0] A[1:0] 00 01 10 11 00 01 10 11 01 00 11 10 01 10 11 00 10 11 00 01 10 11 00 01 11 10 01 00 11 00 01 10 Notes: 1. X = “Don't Care,” 1 = Logic HIGH, 0 = Logic LOW, CE stands for ALL Chip Enables active. BWSx = 0 signifies at least one byte Write Select is active; BWSx = Valid signifies that the desired byte Write selects are asserted. See Write Cycle Description table for details. 2. Write is defined by WE and BWSx. See Write Cycle Description table for details. 3. The DQ and DP pins are controlled by the current cycle and the OE signal. 4. CEN = 1 inserts wait states. 5. Device will power-up deselected and the I/Os in a three-state condition, regardless of OE. 6. OE assumed LOW. Document #: 38-05197 Rev. *C Page 8 of 27 CY7C1370B CY7C1372B Sleep Mode considered valid nor is the completion of the operation guaranteed. The device must be deselected prior to entering the “sleep” mode. CEs, ADSP, and ADSC must remain inactive for the duration of tZZREC after the ZZ input returns LOW. The ZZ input pin is an asynchronous input. Asserting ZZ places the SRAM in a power conservation “sleep” mode. Two clock cycles are required to enter into or exit from this “sleep” mode. While in this mode, data integrity is guaranteed. Accesses pending when entering the “sleep” mode are not ZZ Mode Electrical Characteristics Parameter Description Test Conditions Min. Max. Unit IDDZZ Sleep mode standby current ZZ > VDD – 0.2V 20 mA tZZS Device operation to ZZ ZZ > VDD – 0.2V 2tCYC ns tZZREC ZZ recovery time ZZ < 0.2V 2tCYC ns Write Cycle Descriptions[1, 2] Function (CY7C1370B) WE BWSd BWSc BWSb BWSa Read 1 X X X X Write - No bytes written 0 1 1 1 1 Write Byte 0 - (DQa and DPa) 0 1 1 1 0 Write Byte 1 - (DQb and DPb) 0 1 1 0 1 Write Bytes 1, 0 0 1 1 0 0 Write Byte 2 - (DQc and DPc) 0 1 0 1 1 Write Bytes 2, 0 0 1 0 1 0 Write Bytes 2, 1 0 1 0 0 1 Write Bytes 2, 1, 0 0 1 0 0 0 Write Byte 3 - (DQd and DPd) 0 0 1 1 1 Write Bytes 3, 0 0 0 1 1 0 Write Bytes 3, 1 0 0 1 0 1 Write Bytes 3, 1, 0 0 0 1 0 0 Write Bytes 3, 2 0 0 0 1 1 Write Bytes 3, 2, 0 0 0 0 1 0 Write Bytes 3, 2, 1 0 0 0 0 1 Write All Bytes 0 0 0 0 0 WE BWSb BWSa Read 1 x x Write - No Bytes Written 0 1 1 Write Byte 0 - (DQa and DPa) 0 1 0 Write Byte 1 - (DQb and DPb) 0 0 1 Write Both Bytes 0 0 0 Function (CY7C1372B) Document #: 38-05197 Rev. *C Page 9 of 27 CY7C1370B CY7C1372B IEEE 1149.1 Serial Boundary Scan (JTAG) The CY7C1370B/CY7C1372B incorporates a serial boundary scan Test Access Port (TAP) in the BGA package only. The TQFP package does not offer this functionality. This port operates in accordance with IEEE Standard 1149.1–1900, but does not have the set of functions required for full 1149.1 compliance. These functions from the IEEE specification are excluded because their inclusion places an added delay in the critical speed path of the SRAM. Note that the TAP controller functions in a manner that does not conflict with the operation of other devices using fully 1149.1-compliant TAPs. The TAP operates using JEDEC standard 3.3V I/O logic levels. Disabling the JTAG Feature It is possible to operate the SRAM without using the JTAG feature. To disable the TAP controller, TCK must be tied LOW (VSS) to prevent clocking of the device. TDI and TMS are internally pulled up and may be unconnected. They may alternately be connected to VDD through a pull-up resistor. TDO should be left unconnected. Upon power-up, the device will come up in a reset state which will not interfere with the operation of the device. Test Access Port—Test Clock The test clock is used only with the TAP controller. All inputs are captured on the rising edge of TCK. All outputs are driven from the falling edge of TCK. Test Mode Select The TMS input is used to give commands to the TAP controller and is sampled on the rising edge of TCK. It is allowable to leave this pin unconnected if the TAP is not used. The pin is pulled up internally, resulting in a logic HIGH level. Test Data-In (TDI) The TDI pin is used to serially input information into the registers and can be connected to the input of any of the registers. The register between TDI and TDO is chosen by the instruction that is loaded into the TAP instruction register. For information on loading the instruction register, see the TAP Controller State Diagram. TDI is internally pulled up and can be unconnected if the TAP is unused in an application. TDI is connected to the most significant bit (MSB) on any register. Test Data-Out (TDO) The TDO output pin is used to serially clock data-out from the registers. The output is active depending upon the current state of the TAP state machine (see TAP Controller State Diagram). The output changes on the falling edge of TCK. TDO is connected to the least significant bit (LSB) of any register. Performing a TAP Reset A Reset is performed by forcing TMS HIGH (VDD) for five rising edges of TCK. This RESET does not affect the operation of the SRAM and may be performed while the SRAM is operating. At power-up, the TAP is reset internally to ensure that TDO comes up in a High-Z state. TAP Registers Registers are connected between the TDI and TDO pins and allow data to be scanned into and out of the SRAM test Document #: 38-05197 Rev. *C circuitry. Only one register can be selected at a time through the instruction registers. Data is serially loaded into the TDI pin on the rising edge of TCK. Data is output on the TDO pin on the falling edge of TCK. Instruction Register Three-bit instructions can be serially loaded into the instruction register. This register is loaded when it is placed between the TDI and TDO pins as shown in the TAP Controller Block Diagram. Upon power-up, the instruction register is loaded with the IDCODE instruction. It is also loaded with the IDCODE instruction if the controller is placed in a reset state as described in the previous section. When the TAP controller is in the CaptureIR state, the two least significant bits are loaded with a binary “01” pattern to allow for fault isolation of the board level serial test path. Bypass Register To save time when serially shifting data through registers, it is sometimes advantageous to skip certain states. The bypass register is a single-bit register that can be placed between TDI and TDO pins. This allows data to be shifted through the SRAM with minimal delay. The bypass register is set LOW (VSS) when the BYPASS instruction is executed. Boundary Scan Register The boundary scan register is connected to all the I/O pins on the SRAM. Several no connect (NC) pins are also included in the scan register to reserve pins for higher density devices. The ×36 configuration has a 70-bit-long register, and the ×18 configuration has a 51-bit-long register. The boundary scan register is loaded with the contents of the RAM I/O ring when the TAP controller is in the Capture-DR state and is then placed between the TDI and TDO pins when the controller is moved to the Shift-DR state. The EXTEST, SAMPLE/PRELOAD and SAMPLE Z instructions can be used to capture the contents of the I/O ring. The Boundary Scan Order tables show the order in which the bits are connected. Each bit corresponds to one of the bumps on the SRAM package. The MSB of the register is connected to TDI, and the LSB is connected to TDO. Identification (ID) Register The ID register is loaded with a vendor-specific, 32-bit code during the Capture-DR state when the IDCODE command is loaded in the instruction register. The IDCODE is hardwired into the SRAM and can be shifted out when the TAP controller is in the Shift-DR state. The ID register has a vendor code and other information described in the Identification Register Definitions table. TAP Instruction Set Eight different instructions are possible with the three-bit instruction register. All combinations are listed in the Instruction Code table. Three of these instructions are listed as RESERVED and should not be used. The other five instructions are described in detail below. The TAP controller used in this SRAM is not fully compliant with the 1149.1 convention because some of the mandatory 1149.1 instructions are not fully implemented. The TAP controller cannot be used to load address, data, or control signals into the SRAM and cannot preload the I/O buffers. The Page 10 of 27 CY7C1370B CY7C1372B SRAM does not implement the 1149.1 commands EXTEST or INTEST or the PRELOAD portion of SAMPLE/PRELOAD; rather it performs a capture of the I/O ring when these instructions are executed. When the SAMPLE/PRELOAD instructions are loaded into the instruction register and the TAP controller is in the Capture-DR state, a snapshot of data on the inputs and output pins is captured in the boundary scan register. Instructions are loaded into the TAP controller during the Shift-IR state when the instruction register is placed between TDI and TDO. During this state, instructions are shifted through the instruction register through the TDI and TDO pins. To execute the instruction once it is shifted in, the TAP controller needs to be moved into the Update-IR state. The user must be aware that the TAP controller clock can only operate at a frequency up to 10 MHz, while the SRAM clock operates more than an order of magnitude faster. Because there is a large difference in the clock frequencies, it is possible that during the Capture-DR state, an input or output will undergo a transition. The TAP may then try to capture a signal while in transition (metastable state). This will not harm the device, but there is no guarantee as to the value that will be captured. Repeatable results may not be possible. EXTEST EXTEST is a mandatory 1149.1 instruction which is to be executed whenever the instruction register is loaded with all 0s. EXTEST is not implemented in the TAP controller, and therefore this device is not compliant with the 1149.1 standard. The TAP controller does recognize an all-0 instruction. When an EXTEST instruction is loaded into the instruction register, the SRAM responds as if a SAMPLE/PRELOAD instruction has been loaded. There is one difference between the two instructions. Unlike the SAMPLE/PRELOAD instruction, EXTEST places the SRAM outputs in a High-Z state. IDCODE The IDCODE instruction causes a vendor-specific, 32-bit code to be loaded into the instruction register. It also places the instruction register between the TDI and TDO pins and allows the IDCODE to be shifted out of the device when the TAP controller enters the Shift-DR state. The IDCODE instruction is loaded into the instruction register upon power-up or whenever the TAP controller is given a test logic reset state. SAMPLE Z The SAMPLE Z instruction causes the boundary scan register to be connected between the TDI and TDO pins when the TAP controller is in a Shift-DR state. It also places all SRAM outputs into a High-Z state. SAMPLE/PRELOAD SAMPLE/PRELOAD is a 1149.1 mandatory instruction. The PRELOAD portion of this instruction is not implemented, so the TAP controller is not fully 1149.1-compliant. Document #: 38-05197 Rev. *C To guarantee that the boundary scan register will capture the correct value of a signal, the SRAM signal must be stabilized long enough to meet the TAP controller’s capture set-up plus hold times (tCS and tCH). The SRAM clock input might not be captured correctly if there is no way in a design to stop (or slow) the clock during a SAMPLE/PRELOAD instruction. If this is an issue, it is still possible to capture all other signals and simply ignore the value of the CK and CK# captured in the boundary scan register. Once the data is captured, it is possible to shift out the data by putting the TAP into the Shift-DR state. This places the boundary scan register between the TDI and TDO pins. Note that since the PRELOAD part of the command is not implemented, putting the TAP into the Update to the Update-DR state while performing a SAMPLE/PRELOAD instruction will have the same effect as the Pause-DR command. Bypass When the BYPASS instruction is loaded in the instruction register and the TAP is placed in a Shift-DR state, the bypass register is placed between the TDI and TDO pins. The advantage of the BYPASS instruction is that it shortens the boundary scan path when multiple devices are connected together on a board. Reserved These instructions are not implemented but are reserved for future use. Do not use these instructions. Page 11 of 27 CY7C1370B CY7C1372B TAP Controller State Diagram 1 TEST-LOGIC RESET 1 0 TEST-LOGIC/ 1 1 SELECT IDLE SELECT DR-SCAN IR-SCAN 0 0 1 1 CAPTURE-DR CAPTURE-DR 0 0 SHIFT-DR SHIFT-IR 0 1 0 1 1 EXIT1-DR EXIT1-IR 1 0 0 PAUSE-DR 0 PAUSE-IR 0 1 1 0 0 EXIT2-DR EXIT2-IR 1 1 UPDATE-DR 1 UPDATE-IR 1 0 0 Note: 7. The 0/1 next to each state represents the value at TMS at the rising edge of TCK. Document #: 38-05197 Rev. *C Page 12 of 27 CY7C1370B CY7C1372B TAP Controller Block Diagram 0 Bypass Register Selection Selection Circuitry TDI 2 1 0 2 1 0 2 1 0 Circuitry TDO Instruction Register 29 31 30 . . Identification Register . . . . . Boundary Scan Register TCK TAP Controller TMS TAP Electrical Characteristics Over the Operating Range[8, 9] Parameter Description Test Conditions Min. Max. Unit VOH1 Output HIGH Voltage IOH = −4.0 mA 2.4 V VOH2 Output HIGH Voltage IOH = −100 µA VDD – 0.2 V VOL1 Output LOW Voltage IOL = 8.0 mA 0.4 V VOL2 Output LOW Voltage IOL = 100 µA 0.2 V VIH Input HIGH Voltage 1.7 VDD + 0.3 V VIL Input LOW Voltage −0.5 0.7 V IX Input Load Current −5 5 µA GND ≤ VI ≤ VDDQ Notes: 8. All Voltage referenced to Ground. 9. Overshoot: VIH(AC)