SC16C2550BIA44,518

SC16C2550B 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Rev. 05 — 12 January 2009 Product data sheet 1. General description The SC16C2550B is a two channel Universal Asynchronous Receiver and Transmitter (UART) used for serial data communications. Its principal function is to convert parallel data into serial data and vice versa. The UART can handle serial data rates up to 5 Mbit/s. The SC16C2550B is pin compatible with the ST16C2550. It will power-up to be functionally equivalent to the 16C2450. The SC16C2550B provides enhanced UART functions with 16-byte FIFOs, modem control interface, DMA mode data transfer. The DMA mode data transfer is controlled by the FIFO trigger levels and the TXRDYn and RXRDYn signals. On-board status registers provide the user with error indications and operational status. System interrupts and modem control features may be tailored by software to meet specific user requirements. An internal loopback capability allows on-board diagnostics. Independent programmable baud rate generators are provided to select transmit and receive baud rates. The SC16C2550B operates at 5 V, 3.3 V and 2.5 V and the industrial temperature range, and is available in plastic PLCC44, LQFP48, DIP40 and HVQFN32 packages. 2. Features n n n n n n n n n n n n n 1. 2 channel UART 5 V, 3.3 V and 2.5 V operation 5 V tolerant on input only pins1 Industrial temperature range Pin and functionally compatible to 16C2450 and software compatible with INS8250, SC16C550 Up to 5 Mbit/s data rate at 5 V and 3.3 V and 3 Mbit/s at 2.5 V 16-byte transmit FIFO to reduce the bandwidth requirement of the external CPU 16-byte receive FIFO with error flags to reduce the bandwidth requirement of the external CPU Independent transmit and receive UART control Four selectable Receive FIFO interrupt trigger levels Software selectable baud rate generator Standard asynchronous error and framing bits (Start, Stop and Parity Overrun Break) Transmit, Receive, Line Status and Data Set interrupts independently controlled For data bus pins D7 to D0, see Table 23 “Limiting values”. SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs n Fully programmable character formatting: u 5-bit, 6-bit, 7-bit or 8-bit characters u Even, odd or no-parity formats u 1, 11⁄2 or 2-stop bit u Baud generation (DC to 5 Mbit/s) n False start-bit detection n Complete status reporting capabilities n 3-state output TTL drive capabilities for bidirectional data bus and control bus n Line break generation and detection n Internal diagnostic capabilities: u Loopback controls for communications link fault isolation n Prioritized interrupt system controls n Modem control functions (CTS, RTS, DSR, DTR, RI, DCD) 3. Ordering information Table 1. Ordering information Type number Package Name Description Version SC16C2550BIA44 PLCC44 plastic leaded chip carrier; 44 leads SOT187-2 SC16C2550BIBS HVQFN32 plastic thermal enhanced very thin quad flat package; no leads; 32 terminals; body 5 × 5 × 0.85 mm SOT617-1 SC16C2550BIB48 LQFP48 plastic low profile quad flat package; 48 leads; body 7 × 7 × 1.4 mm SOT313-2 SC16C2550BIN40 DIP40 plastic dual in-line package; 40 leads (600 mil) SOT129-1 3.1 Ordering options Table 2. Ordering options Type number Topside mark SC16C2550BIA44 SC16C2550BIA44 SC16C2550BIBS 2550B SC16C2550BIB48 16C2550B SC16C2550BIN40 SC16C2550BIN40 SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 2 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 4. Block diagram SC16C2550B A0 to A2 CSA CSB TRANSMIT SHIFT REGISTER TXA, TXB RECEIVE FIFO REGISTER RECEIVE SHIFT REGISTER RXA, RXB DATA BUS AND CONTROL LOGIC REGISTER SELECT LOGIC INTERCONNECT BUS LINES AND CONTROL SIGNALS D0 to D7 IOR IOW RESET TRANSMIT FIFO REGISTER DTRA, DTRB RTSA, RTSB OP2A, OP2B INTA, INTB TXRDYA, TXRDYB RXRDYA, RXRDYB INTERRUPT CONTROL LOGIC CLOCK AND BAUD RATE GENERATOR MODEM CONTROL LOGIC CTSA, CTSB RIA, RIB CDA, CDB DSRA, DSRB 002aaa595 XTAL1 Fig 1. XTAL2 Block diagram of SC16C2550B SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 3 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 5. Pinning information 25 CTSA 26 VCC 27 D0 28 D1 29 D2 30 D3 32 D5 terminal 1 index area 31 D4 5.1 Pinning D6 1 24 RESET D7 2 23 RTSA RXB 3 22 OP2A RXA 4 TXA 5 TXB 6 19 A0 OP2B 7 18 A1 CSA 8 17 A2 21 INTA 20 INTB CTSB 16 RTSB 15 IOR 14 GND 13 IOW 12 XTAL2 11 9 CSB XTAL1 10 SC16C2550BIBS 002aab746 Transparent top view Fig 2. Pin configuration for HVQFN32 SC16C2550BIN40 D0 1 40 VCC D1 2 39 RIA D2 3 38 CDA D3 4 37 DSRA D4 5 36 CTSA D5 6 35 RESET D6 7 34 DTRB D7 8 33 DTRA RXB 9 32 RTSA RXA 10 31 OP2A TXA 11 30 INTA TXB 12 29 INTB OP2B 13 28 A0 CSA 14 27 A1 CSB 15 26 A2 XTAL1 16 25 CTSB XTAL2 17 24 RTSB IOW 18 23 RIB CDB 19 22 DSRB GND 20 21 IOR 002aaa596 Fig 3. Pin configuration for DIP40 SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 4 of 43 SC16C2550B NXP Semiconductors 1 40 CTSA D0 TXRDYA 2 41 DSRA D1 3 42 CDA D2 4 43 RIA D3 5 44 VCC D4 6 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs D5 7 39 RESET D6 8 38 DTRB D7 9 37 DTRA RXB 10 36 RTSA RXA 11 35 OP2A SC16C2550BIA44 TXRDYB 12 33 INTA TXB 14 32 INTB CTSB 28 RTSB 27 RIB 26 IOR 24 DSRB 25 RXRDYB 23 GND 22 37 n.c. 38 CTSA 39 DSRA 40 CDA 42 VCC 41 RIA 43 TXRDYA 44 D0 45 D1 46 D2 47 D3 48 D4 D5 1 36 RESET D6 2 35 DTRB D7 3 34 DTRA RXB 4 33 RTSA RXA 5 32 OP2A TXRDYB 6 TXA 7 TXB 8 29 INTB OP2B 9 28 A0 CSA 10 27 A1 CSB 11 26 A2 n.c. 12 25 n.c. 31 RXRDYA n.c. 24 CTSB 23 30 INTA RTSB 22 RIB 21 IOR 19 DSRB 20 RXRDYB 18 GND 17 CDB 16 IOW 15 SC16C2550BIB48 002aaa598 Pin configuration for LQFP48 SC16C2550B_5 Product data sheet 002aaa597 Pin configuration for PLCC44 XTAL1 13 Fig 5. CDB 21 29 A2 IOW 20 30 A1 CSB 17 XTAL2 19 31 A0 CSA 16 XTAL1 18 OP2B 15 XTAL2 14 Fig 4. 34 RXRDYA TXA 13 © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 5 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 5.2 Pin description Table 3. Pin description Symbol Pin Type Description HVQFN32 DIP40 PLCC44 LQFP48 A0 19 28 31 28 I Address 0 select bit. Internal register address selection. A1 18 27 30 27 I Address 1 select bit. Internal register address selection. A2 17 26 29 26 I Address 2 select bit. Internal register address selection. CSA 8 14 16 10 I CSB 9 15 17 11 I Chip Select A, B (active LOW). This function is associated with individual channels, A through B. These pins enable data transfers between the user CPU and the SC16C2550B for the channel(s) addressed. Individual UART sections (A, B) are addressed by providing a logic 0 on the respective CSA, CSB pin. D0 27 1 2 44 I/O D1 28 2 3 45 I/O D2 29 3 4 46 I/O D3 30 4 5 47 I/O D4 31 5 6 48 I/O D5 32 6 7 1 I/O D6 1 7 8 2 I/O D7 2 8 9 3 I/O GND 13 20 22 17 I Signal and power ground. INTA 21 30 33 30 O INTB 20 29 32 29 O Interrupt A, B (3-state). This function is associated with individual channel interrupts, INTA, INTB. INTA, INTB are enabled when MCR bit 3 is set to a logic 1, interrupts are enabled in the Interrupt Enable Register (IER) and is active when an interrupt condition exists. Interrupt conditions include: receiver errors, available receiver buffer data, transmit buffer empty or when a modem status flag is detected. IOR 14 21 24 19 I Read strobe (active LOW strobe). A logic 0 transition on this pin will load the contents of an internal register defined by address bits A0 to A2 onto the SC16C2550B data bus (D0 to D7) for access by external CPU. IOW 12 18 20 15 I Write strobe (active LOW strobe). A logic 0 transition on this pin will transfer the contents of the data bus (D0 to D7) from the external CPU to an internal register that is defined by address bits A0 to A2. OP2A 22 31 35 32 O OP2B 7 13 15 9 O Output 2 (user-defined). This function is associated with individual channels, A through B. The state at these pin(s) are defined by the user and through MCR register bit 3. INTA, INTB are set to the active mode and OP2 to logic 0 when MCR[3] is set to a logic 1. INTA, INTB are set to the 3-state mode and OP2 to a logic 1 when MCR[3] is set to a logic 0. See Table 18 “Modem Control Register bits description”, bit 3 (MCR[3]). Since these bits control both the INTA, INTB operation and OP2 outputs, only one function should be used at one time, INT or OP2. Data bus (bidirectional). These pins are the 8-bit, 3-state data bus for transferring information to or from the controlling CPU. D0 is the least significant bit and the first data bit in a transmit or receive serial data stream. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 6 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 3. Pin description …continued Symbol Pin Type Description HVQFN32 DIP40 PLCC44 LQFP48 RESET 24 35 39 36 I Reset (active HIGH). A logic 1 on this pin will reset the internal registers and all the outputs. The UART transmitter output and the receiver input will be disabled during reset time. (See Section 7.10 “SC16C2550B external reset condition” for initialization details.) RXRDYA - - 34 31 O RXRDYB - - 23 18 O Receive Ready A, B (active LOW). This function is associated with PLCC44 and LQFP48 packages only. This function provides the RX FIFO/RHR status for individual receive channels (A-B). RXRDYn is primarily intended for monitoring DMA mode 1 transfers for the receive data FIFOs. A logic 0 indicates there is a receive data to read/upload, that is, receive ready status with one or more RX characters available in the FIFO/RHR. This pin is a logic 1 when the FIFO/RHR is empty or when the programmed trigger level has not been reached. This signal can also be used for single mode transfers (DMA mode 0). TXRDYA - - 1 43 O TXRDYB - - 12 6 O VCC 26 40 44 42 I Power supply input. XTAL1 10 16 18 13 I Crystal or external clock input. Functions as a crystal input or as an external clock input. A crystal can be connected between this pin and XTAL2 to form an internal oscillator circuit. Alternatively, an external clock can be connected to this pin to provide custom data rates. (See Section 6.5 “Programmable baud rate generator”.) See Figure 6. XTAL2 11 17 19 14 O Output of the crystal oscillator or buffered clock. (See also XTAL1.) Crystal oscillator output or buffered clock output. Should be left open if an external clock is connected to XTAL1. For extended frequency operation, this pin should be tied to VCC via a 2 kΩ resistor. CDA - 38 42 40 I CDB - 19 21 16 I Carrier Detect (active LOW). These inputs are associated with individual UART channels A through B. A logic 0 on this pin indicates that a carrier has been detected by the modem for that channel. CTSA 25 36 40 38 I CTSB 16 25 28 23 I Transmit Ready A, B (active LOW). This function is associated with PLCC44 and LQFP48 packages only. These outputs provide the TX FIFO/THR status for individual transmit channels (A, B). TXRDYn is primarily intended for monitoring DMA mode 1 transfers for the transmit data FIFOs. An individual channel’s TXRDYA, TXRDYB buffer ready status is indicated by logic 0, that is, at least one location is empty and available in the FIFO or THR. This pin goes to a logic 1 (DMA mode 1) when there are no more empty locations in the FIFO or THR. This signal can also be used for single mode transfers (DMA mode 0). Clear to Send (active LOW). These inputs are associated with individual UART channels, A through B. A logic 0 on the CTSn pin indicates the modem or data set is ready to accept transmit data from the SC16C2550B. Status can be tested by reading MSR[4]. This pin has no effect on the UART’s transmit or receive operation. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 7 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 3. Pin description …continued Symbol Pin Type Description Data Set Ready (active LOW). These inputs are associated with individual UART channels, A through B. A logic 0 on this pin indicates the modem or data set is powered-on and is ready for data exchange with the UART. This pin has no effect on the UART’s transmit or receive operation. HVQFN32 DIP40 PLCC44 LQFP48 DSRA - 37 41 39 I DSRB - 22 25 20 I DTRA - 33 37 34 O DTRB - 34 38 35 O RIA - 39 43 41 I RIB - 23 26 21 I RTSA 23 32 36 33 O RTSB 15 24 27 22 O RXA 4 10 11 5 I RXB 3 9 10 4 I TXA 5 11 13 7 O TXB 6 12 14 8 O n.c. - - - 12, 24, 25, 37 - Data Terminal Ready (active LOW). These outputs are associated with individual UART channels, A through B. A logic 0 on this pin indicates that the SC16C2550B is powered-on and ready. This pin can be controlled via the Modem Control Register. Writing a logic 1 to MCR[0] will set the DTRn output to logic 0, enabling the modem. This pin will be a logic 1 after writing a logic 0 to MCR[0] or after a reset. This pin has no effect on the UART’s transmit or receive operation. Ring Indicator (active LOW). These inputs are associated with individual UART channels, A through B. A logic 0 on this pin indicates the modem has received a ringing signal from the telephone line. A logic 1 transition on this input pin will generate an interrupt. Request to Send (active LOW). These outputs are associated with individual UART channels, A through B. A logic 0 on the RTSn pin indicates the transmitter has data ready and waiting to send. Writing a logic 1 in the Modem Control Register MCR[1] will set this pin to a logic 0, indicating data is available. After a reset this pin will be set to a logic 1. This pin has no effect on the UART’s transmit or receive operation. Receive data A, B. These inputs are associated with individual serial channel data to the SC16C2550B receive input circuits, A and B. The RXn signal will be a logic 1 during reset, idle (no data) or when the transmitter is disabled. During the local Loopback mode, the RXn input pin is disabled and TX data is connected to the UART RX input, internally. Transmit data A, B. These outputs are associated with individual serial transmit channel data from the SC16C2550B. The TXn signal will be a logic 1 during reset, idle (no data) or when the transmitter is disabled. During the local Loopback mode, the TXn output pin is disabled and TX data is internally connected to the UART RX input. not connected SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 8 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 6. Functional description The SC16C2550B provides serial asynchronous receive data synchronization, parallel-to-serial and serial-to-parallel data conversions for both the transmitter and receiver sections. These functions are necessary for converting the serial data stream into parallel data that is required with digital data systems. Synchronization for the serial data stream is accomplished by adding start and stop bits to the transmit data to form a data character (character orientated protocol). Data integrity is insured by attaching a parity bit to the data character. The parity bit is checked by the receiver for any transmission bit errors. The electronic circuitry to provide all these functions is fairly complex, especially when manufactured on a single integrated silicon chip. The SC16C2550B represents such an integration with greatly enhanced features. The SC16C2550B is fabricated with an advanced CMOS process. The SC16C2550B is an upward solution that provides a dual UART capability with 16 bytes of transmit and receive FIFO memory, instead of none in the 16C2450. The SC16C2550B is designed to work with high speed modems and shared network environments that require fast data processing time. Increased performance is realized in the SC16C2550B by the transmit and receive FIFOs. This allows the external processor to handle more networking tasks within a given time. For example, the ST16C2450 without a receive FIFO, will require unloading of the RHR in 93 microseconds (this example uses a character length of 11 bits, including start/stop bits at 115.2 kbit/s). This means the external CPU will have to service the receive FIFO less than every 100 microseconds. However, with the 16-byte FIFO in the SC16C2550B, the data buffer will not require unloading/loading for 1.53 ms. This increases the service interval, giving the external CPU additional time for other applications and reducing the overall UART interrupt servicing time. In addition, the four selectable receive FIFO trigger interrupt levels are uniquely provided for maximum data throughput performance especially when operating in a multi-channel environment. The FIFO memory greatly reduces the bandwidth requirement of the external controlling CPU, increases performance and reduces power consumption. The SC16C2550B is capable of operation up to 5 Mbit/s with a 80 MHz clock. With a crystal or external clock input of 7.3728 MHz, the user can select data rates up to 460.8 kbit/s. The rich feature set of the SC16C2550B is available through internal registers. Selectable receive FIFO trigger levels, selectable TX and RX baud rates and modem interface controls are all standard features. Following a power-on reset or an external reset, the SC16C2550B is software compatible with the previous generation, ST16C2450. 6.1 UART A-B functions The UART provides the user with the capability to bidirectionally transfer information between an external CPU, the SC16C2550B package and an external serial device. A logic 0 on chip select pins CSA and/or CSB allows the user to configure, send data, and/or receive data via UART channels A through B. Individual channel select functions are shown in Table 4. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 9 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 4. Serial port selection Chip Select Function CSA, CSB = 1 none CSA = 0 UART channel A CSB = 0 UART channel B 6.2 Internal registers The SC16C2550B provides two sets of internal registers (A and B) consisting of 12 registers each for monitoring and controlling the functions of each channel of the UART. These registers are shown in Table 5. The UART registers function as data holding registers (THR/RHR), interrupt status and control registers (IER/ISR), a FIFO Control Register (FCR), line status and control registers (LCR/LSR), modem status and control registers (MCR/MSR), programmable data rate (clock) control registers (DLL/DLM) and a user-accessible Scratchpad Register (SPR). Table 5. A2 Internal registers decoding A1 A0 READ mode WRITE mode General register set (THR/RHR, IER/ISR, MCR/MSR, FCR, LCR/LSR, SPR)[1] 0 0 0 Receive Holding Register Transmit Holding Register 0 0 1 Interrupt Enable Register Interrupt Enable Register 0 1 0 Interrupt Status Register FIFO Control Register 0 1 1 Line Control Register Line Control Register 1 0 0 Modem Control Register Modem Control Register 1 0 1 Line Status Register n/a 1 1 0 Modem Status Register n/a 1 1 1 Scratchpad Register Scratchpad Register Baud rate register set (DLL/DLM)[2] 0 0 0 LSB of Divisor Latch LSB of Divisor Latch 0 0 1 MSB of Divisor Latch MSB of Divisor Latch [1] These registers are accessible only when LCR[7] is a logic 0. [2] These registers are accessible only when LCR[7] is a logic 1. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 10 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 6.3 FIFO operation The 16-byte transmit and receive data FIFOs are enabled by the FIFO Control Register (FCR) bit 0. The user can set the receive trigger level via FCR bits 7:6, but not the transmit trigger level. The receiver FIFO section includes a time-out function to ensure data is delivered to the external CPU. An interrupt is generated whenever the Receive Holding Register (RHR) has not been read following the loading of a character or the receive trigger level has not been reached. Table 6. Flow control mechanism Selected trigger level (characters) INTn pin activation 1 1 4 4 8 8 14 14 6.4 Hardware/software and time-out interrupts The interrupts are enabled by IER[3:0]. Care must be taken when handling these interrupts. Following a reset, if Interrupt Enable Register (IER) bit 1 = 1, the SC16C2550B will issue a Transmit Holding Register interrupt. This interrupt must be serviced prior to continuing operations. The ISR register provides the current singular highest priority interrupt only. A condition can exist where a higher priority interrupt may mask the lower priority interrupt(s). Only after servicing the higher pending interrupt will the lower priority interrupt(s) be reflected in the status register. Servicing the interrupt without investigating further interrupt conditions can result in data errors. When two interrupt conditions have the same priority, it is important to service these interrupts correctly. Receive Data Ready and Receive Time Out have the same interrupt priority (when enabled by IER[0]). The receiver issues an interrupt after the number of characters have reached the programmed trigger level. In this case, the SC16C2550B FIFO may hold more characters than the programmed trigger level. Following the removal of a data byte, the user should re-check LSR[0] for additional characters. A Receive Time Out will not occur if the receive FIFO is empty. The time-out counter is reset at the center of each stop bit received or each time the Receive Holding Register (RHR) is read. The actual time-out value is 4 character time, including data information length, start bit, parity bit and the size of stop bit, that is, 1×, 1.5× or 2× bit times. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 11 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 6.5 Programmable baud rate generator The SC16C2550B supports high speed modem technologies that have increased input data rates by employing data compression schemes. For example, a 33.6 kbit/s modem that employs data compression may require a 115.2 kbit/s input data rate. A 128.0 kbit/s ISDN modem that supports data compression may need an input data rate of 460.8 kbit/s. The SC16C2550B can support a standard data rate of 921.6 kbit/s. A single baud rate generator is provided for the transmitter and receiver, allowing independent TX/RX channel control. The programmable baud rate generator is capable of operating with a frequency of up to 80 MHz. To obtain maximum data rate, it is necessary to use full rail swing on the clock input. The SC16C2550B can be configured for internal or external clock operation. For internal clock oscillator operation, an industry standard microprocessor crystal is connected externally between the XTAL1 and XTAL2 pins. Alternatively, an external clock can be connected to the XTAL1 pin to clock the internal baud rate generator for standard or custom rates (see Table 7). The generator divides the input 16× clock by any divisor from 1 to (216 − 1). The SC16C2550B divides the basic external clock by 16. The basic 16× clock provides table rates to support standard and custom applications using the same system design. The rate table is configured via the DLL and DLM internal register functions. Customized baud rates can be achieved by selecting the proper divisor values for the MSB and LSB sections of baud rate generator. Programming the baud rate generator registers DLM (MSB) and DLL (LSB) provides a user capability for selecting the desired final baud rate. The example in Table 7 shows the selectable baud rate table available when using a 1.8432 MHz external clock input. XTAL1 XTAL2 X1 1.8432 MHz C1 22 pF XTAL1 XTAL2 X1 1.8432 MHz C2 33 pF C1 22 pF 1.5 kΩ C2 47 pF 002aaa870 Fig 6. Crystal oscillator connection SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 12 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 7. Baud rate generator programming table using a 1.8432 MHz clock Output baud rate (bit/s) Output 16× clock divisor (decimal) Output 16× clock divisor (hexadecimal) DLM program value (hexadecimal) DLL program value (hexadecimal) 50 2304 900 09 00 75 1536 600 06 00 110 1047 417 04 17 150 768 300 03 00 300 384 180 01 80 600 192 C0 00 C0 1200 96 60 00 60 2400 48 30 00 30 3600 32 20 00 20 4800 24 18 00 18 7200 16 10 00 10 9600 12 0C 00 0C 19.2 k 6 06 00 06 38.4 k 3 03 00 03 57.6 k 2 02 00 02 115.2 k 1 01 00 01 6.6 DMA operation The SC16C2550B FIFO trigger level provides additional flexibility to the user for block mode operation. LSR[6:5] provide an indication when the transmitter is empty or has an empty location(s). The user can optionally operate the transmit and receive FIFOs in the DMA mode (FCR[3]). When the transmit and receive FIFOs are enabled and the DMA mode is de-activated (DMA Mode 0), the SC16C2550B activates the interrupt output pin (INTn) for each data transmit or receive operation. When DMA mode is activated (DMA Mode 1), the user takes the advantage of block mode operation by loading or unloading the FIFO in a block sequence determined by the receive trigger level and the transmit FIFO. In this mode, the SC16C2550B sets the TXRDYn (or RXRDYn) output pin when characters in the transmit FIFO is below 16 or the characters in the receive FIFOs are above the receive trigger level. 6.7 Loopback mode The internal loopback capability allows on-board diagnostics. In the Loopback mode, the normal modem interface pins are disconnected and reconfigured for loopback internally (see Figure 7). MCR[3:0] register bits are used for controlling loopback diagnostic testing. In the Loopback mode, the transmitter output (TX) and the receiver input (RX) are disconnected from their associated interface pins and instead are connected together internally. The CTS, DSR, CD and RI are disconnected from their normal modem control input pins and instead are connected internally to RTS, DTR, MCR[3] (OP2) and MCR[2] (OP1). Loopback test data is entered into the transmit holding register via the user data bus interface, D0 through D7. The transmit UART serializes the data and passes the serial data to the receive UART via the internal loopback connection. The receive UART SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 13 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs converts the serial data back into parallel data that is then made available at the user data interface D0 through D7. The user optionally compares the received data to the initial transmitted data for verifying error-free operation of the UART TX/RX circuits. In this mode, the receiver and transmitter interrupts are fully operational. The modem control interrupts are also operational. SC16C2550B D0 to D7 IOR IOW RESET TRANSMIT FIFO REGISTERS TRANSMIT SHIFT REGISTER TXA, TXB DATA BUS AND CONTROL LOGIC A0 to A2 CSA, CSB REGISTER SELECT LOGIC INTERCONNECT BUS LINES AND CONTROL SIGNALS MCR[4] = 1 RECEIVE FIFO REGISTERS RECEIVE SHIFT REGISTER RXA, RXB RTSA, RTSB CTSA, CTSB DTRA, DTRB MODEM CONTROL LOGIC INTA, INTB TXRDYA, TXRDYB RXRDYA, RXRDYB INTERRUPT CONTROL LOGIC DSRA, DSRB (OP1A, OP1B) CLOCK AND BAUD RATE GENERATOR RIA, RIB (OP2A, OP2B) CDA, CDB 002aaa599 XTAL1 Fig 7. XTAL2 Internal Loopback mode diagram SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 14 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7. Register descriptions Table 8 details the assigned bit functions for the SC16C2550B internal registers. The assigned bit functions are more fully defined in Section 7.1 through Section 7.10. Table 8. SC16C2550B internal registers A2 A0 A1 Register Default[1] Bit 7 General register Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 bit 2 bit 1 bit 0 transmit holding register interrupt receive holding register set[2] 0 0 0 RHR XX bit 7 bit 6 0 0 0 THR XX bit 7 bit 6 bit 5 bit 4 bit 3 0 0 1 IER 00 0 0 0 0 modem receive status line interrupt status interrupt 0 1 0 FCR 00 RCVR trigger (MSB) RCVR trigger (LSB) reserved reserved DMA 0 0 mode select XMIT FIFO reset RCVR FIFO reset FIFOs enable 0 1 0 ISR 01 FIFOs enabled FIFOs enabled 0 INT priority bit 2 INT priority bit 1 INT priority bit 0 INT status 0 1 1 LCR 00 divisor latch enable set break set parity even parity parity enable stop bits word length bit 1 1 0 0 MCR 00 0 0 loop back OP2/INT (OP1) enable RTS DTR 1 0 1 LSR 60 FIFO data error THR and THR TSR empty empty break interrupt framing error parity error overrun error receive data ready 1 1 0 MSR X0 CD RI DSR CTS ∆CD ∆RI ∆DSR ∆CTS 1 1 1 SPR FF bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 0 word length bit 0 Special register set[3] 0 0 0 DLL XX bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 0 1 DLM XX bit 15 bit 14 bit 13 bit 12 bit 11 bit 10 bit 9 bit 8 [1] The value shown represents the register’s initialized hexadecimal value; X = not applicable. [2] Accessible only when LCR[7] is logic 0. [3] Baud rate registers accessible only when LCR[7] is logic 1. 7.1 Transmit Holding Register (THR) and Receive Holding Register (RHR) The serial transmitter section consists of an 8-bit Transmit Hold Register (THR) and Transmit Shift Register (TSR). The status of the THR is provided in the Line Status Register (LSR). Writing to the THR transfers the contents of the data bus (D7 through D0) to the TSR and UART via the THR, providing that the THR is empty. The THR empty flag in the LSR register will be set to a logic 1 when the transmitter is empty or when data is transferred to the TSR. Note that a write operation can be performed when the THR empty flag is set (logic 0 = at least one byte in FIFO/THR, logic 1 = FIFO/THR empty). The serial receive section also contains an 8-bit Receive Holding Register (RHR) and a Receive Serial Shift Register (RSR). Receive data is removed from the SC16C2550B and receive FIFO by reading the RHR register. The receive section provides a mechanism to SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 15 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs prevent false starts. On the falling edge of a start or false start bit, an internal receiver counter starts counting clocks at the 16× clock rate. After 71⁄2 clocks, the start bit time should be shifted to the center of the start bit. At this time the start bit is sampled and if it is still a logic 0 it is validated. Evaluating the start bit in this manner prevents the receiver from assembling a false character. Receiver status codes will be posted in the LSR. 7.2 Interrupt Enable Register (IER) The Interrupt Enable Register (IER) masks the interrupts from receiver ready, transmitter empty, line status and modem status registers. These interrupts would normally be seen on the INTA, INTB output pins. Table 9. Interrupt Enable Register bits description Bit Symbol Description 7:4 IER[7:4] not used 3 IER[3] Modem Status Interrupt. This interrupt will be issued whenever there is a modem status change as reflected in MSR[3:0]. logic 0 = disable the Modem Status Register interrupt (normal default condition) logic 1 = enable the Modem Status Register interrupt 2 IER[2] Receive Line Status interrupt. This interrupt will be issued whenever a receive data error condition exists as reflected in LSR[4:1]. logic 0 = disable the receiver line status interrupt (normal default condition) logic 1 = enable the receiver line status interrupt 1 IER[1] Transmit Holding Register interrupt. In the 16C450 mode, this interrupt will be issued whenever the THR is empty and is associated with LSR[5]. In the FIFO modes, this interrupt will be issued whenever the FIFO is empty. logic 0 = disable the Transmit Holding Register Empty (TXRDY) interrupt (normal default condition) logic 1 = enable the TXRDY (ISR level 3) interrupt 0 IER[0] Receive Holding Register. In the 16C450 mode, this interrupt will be issued when the RHR has data or is cleared when the RHR is empty. In the FIFO mode, this interrupt will be issued when the FIFO has reached the programmed trigger level or is cleared when the FIFO drops below the trigger level. logic 0 = disable the receiver ready (ISR level 2, RXRDY) interrupt (normal default condition) logic 1 = enable the RXRDY (ISR level 2) interrupt SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 16 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7.2.1 IER versus Transmit/Receive FIFO interrupt mode operation When the receive FIFO (FCR[0] = logic 1) and receive interrupts (IER[0] = logic 1) are enabled, the receive interrupts and register status will reflect the following: • The receive RXRDY interrupt (Level 2 ISR interrupt) is issued to the external CPU when the receive FIFO has reached the programmed trigger level. It will be cleared when the receive FIFO drops below the programmed trigger level. • Receive FIFO status will also be reflected in the user accessible ISR register when the receive FIFO trigger level is reached. Both the ISR register receive status bit and the interrupt will be cleared when the FIFO drops below the trigger level. • The receive data ready bit (LSR[0]) is set as soon as a character is transferred from the shift register (RSR) to the receive FIFO. It is reset when the FIFO is empty. • When the Transmit FIFO and interrupts are enabled, an interrupt is generated when the transmit FIFO is empty due to the unloading of the data by the TSR and UART for transmission via the transmission media. The interrupt is cleared either by reading the ISR register or by loading the THR with new data characters. 7.2.2 IER versus Receive/Transmit FIFO polled mode operation When FCR[0] = logic 1, resetting IER[3:0] enables the SC16C2550B in the FIFO polled mode of operation. In this mode, interrupts are not generated and the user must poll the LSR register for TX and/or RX data status. Since the receiver and transmitter have separate bits in the LSR either or both can be used in the polled mode by selecting respective transmit or receive control bit(s). • • • • • LSR[0] will be a logic 1 as long as there is one byte in the receive FIFO. LSR[4:1] will provide the type of receive errors or a receive break, if encountered. LSR[5] will indicate when the transmit FIFO is empty. LSR[6] will indicate when both the transmit FIFO and transmit shift register are empty. LSR[7] will show if any FIFO data errors occurred. 7.3 FIFO Control Register (FCR) This register is used to enable the FIFOs, clear the FIFOs, set the receive FIFO trigger levels and select the DMA mode. 7.3.1 DMA mode 7.3.1.1 Mode 0 (FCR bit 3 = 0) Set and enable the interrupt for each single transmit or receive operation and is similar to the 16C450 mode. Transmit Ready (TXRDYn) on PLCC44 and LQFP48 packages will go to a logic 0 whenever the FIFO (THR, if FIFO is not enabled) is empty. Receive Ready (RXRDYn) on PLCC44 and LQFP48 packages will go to a logic 0 whenever the Receive Holding Register (RHR) is loaded with a character. 7.3.1.2 Mode 1 (FCR bit 3 = 1) Set and enable the interrupt in a block mode operation. The transmit interrupt is set when the transmit FIFO is empty. TXRDYn on PLCC44 and LQFP48 packages remains a logic 0 as long as one empty FIFO location is available. The receive interrupt is set when the receive FIFO fills to the programmed trigger level. However, the FIFO continues to fill SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 17 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs regardless of the programmed level until the FIFO is full. RXRDY on PLCC44 and LQFP48 packages transitions LOW when the FIFO reaches the trigger level and transitions HIGH when the FIFO empties. 7.3.2 FIFO mode Table 10. FIFO Control Register bits description Bit Symbol Description 7:6 FCR[7:6] RCVR trigger. These bits are used to set the trigger level for the receive FIFO interrupt. logic 0 (or cleared) = normal default condition logic 1 = RX trigger level An interrupt is generated when the number of characters in the FIFO equals the programmed trigger level. However, the FIFO will continue to be loaded until it is full. Refer to Table 11. 5:4 FCR[5:4] Not used; initialized to logic 0. 3 FCR[3] DMA mode select. logic 0 = set DMA mode ‘0’ logic 1 = set DMA mode ‘1’ Transmit operation in mode ‘0’: When the SC16C2550B is in the 16C450 mode (FIFOs disabled; FCR[0] = logic 0) or in the FIFO mode (FIFOs enabled; FCR[0] = logic 1; FCR[3] = logic 0) and when there are no characters in the transmit FIFO or Transmit Holding Register, the TXRDYn pin in PLCC44 or LQFP48 packages will be a logic 0. Once active, the TXRDYn pin will go to a logic 1 after the first character is loaded into the Transmit Holding Register. Receive operation in mode ‘0’: When the SC16C2550B is in mode ‘0’ (FCR[0] = logic 0) or in the FIFO mode (FCR[3] = logic 0) and there is at least one character in the receive FIFO, the RXRDYn pin will be a logic 0. Once active, the RXRDYn pin on PLCC44 and LQFP48 packages will go to a logic 1 when there are no more characters in the receiver. Transmit operation in mode ‘1’: When the SC16C2550B is in FIFO mode (FCR[0] = logic 1; FCR[3] = logic 1), the TXRDYn pin on PLCC44 and LQFP48 packages will be a logic 1 when the transmit FIFO is completely full. It will be a logic 0 if one or more FIFO locations are empty. Receive operation in mode ‘1’: When the SC16C2550B is in FIFO mode (FCR[0] = logic 1; FCR[3] = logic 1) and the trigger level has been reached or a Receive Time-out has occurred, the RXRDYn pin on PLCC44 and LQFP48 packages will go to a logic 0. Once activated, it will go to a logic 1 after there are no more characters in the FIFO. 2 FCR[2] XMIT FIFO reset. logic 0 = Transmit FIFO not reset (normal default condition). logic 1 = clears the contents of the transmit FIFO and resets the FIFO counter logic (the Transmit Shift Register is not cleared or altered). This bit will return to a logic 0 after clearing the FIFO. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 18 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 10. FIFO Control Register bits description …continued Bit Symbol Description 1 FCR[1] RCVR FIFO reset. logic 0 = Receive FIFO not reset (normal default condition) logic 1 = clears the contents of the receive FIFO and resets the FIFO counter logic (the Receive Shift Register is not cleared or altered). This bit will return to a logic 0 after clearing the FIFO. 0 FCR[0] FIFOs enabled. logic 0 = disable the transmit and receive FIFO (normal default condition) logic 1 = enable the transmit and receive FIFO. This bit must be a ‘1’ when other FCR bits are written to or they will not be programmed. Table 11. RCVR trigger levels FCR[7] FCR[6] RX FIFO trigger level 0 0 01 0 1 04 1 0 08 1 1 14 7.4 Interrupt Status Register (ISR) The SC16C2550B provides four levels of prioritized interrupts to minimize external software interaction. The Interrupt Status Register (ISR) provides the user with four interrupt status bits. Performing a read cycle on the ISR will provide the user with the highest pending interrupt level to be serviced. No other interrupts are acknowledged until the pending interrupt is serviced. A lower level interrupt may be seen after servicing the higher level interrupt and re-reading the interrupt status bits. Table 12 “Interrupt source” shows the data values (bits 3:0) for the four prioritized interrupt levels and the interrupt sources associated with each of these interrupt levels. Table 12. Interrupt source Priority level ISR[3] ISR[2] ISR[1] ISR[0] Source of the interrupt 1 0 1 1 0 LSR (Receiver Line Status Register) 2 0 1 0 0 RXRDY (Received Data Ready) 2 1 1 0 0 RXRDY (Receive Data Time-out) 3 0 0 1 0 TXRDY (Transmitter Holding Register empty) 4 0 0 0 0 MSR (Modem Status Register) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 19 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 13. Interrupt Status Register bits description Bit Symbol Description 7:6 ISR[7:6] FIFOs enabled. These bits are set to a logic 0 when the FIFOs are not being used in the 16C450 mode. They are set to a logic 1 when the FIFOs are enabled in the SC16C2550B mode. logic 0 or cleared = default condition 5:4 ISR[5:4] not used 3:1 ISR[3:1] INT priority bits 2:0. These bits indicate the source for a pending interrupt at interrupt priority levels 1, 2 and 3 (see Table 12). 0 ISR[0] INT status. logic 0 or cleared = default condition logic 0 = an interrupt is pending and the ISR contents may be used as a pointer to the appropriate interrupt service routine logic 1 = no interrupt pending (normal default condition) 7.5 Line Control Register (LCR) The Line Control Register is used to specify the asynchronous data communication format. The word length, the number of stop bits and the parity are selected by writing the appropriate bits in this register. Table 14. Line Control Register bits description Bit Symbol Description 7 LCR[7] Divisor latch enable. The internal baud rate counter latch and Enhanced Feature mode enable. logic 0 = divisor latch disabled (normal default condition) logic 1 = divisor latch enabled 6 LCR[6] Set break. When enabled, the Break control bit causes a break condition to be transmitted (the TX output is forced to a logic 0 state). This condition exists until disabled by setting LCR[6] to a logic 0. logic 0 = no TX break condition (normal default condition) logic 1 = forces the transmitter output (TX) to a logic 0 for alerting the remote receiver to a line break condition 5:3 LCR[5:3] Programs the parity conditions (see Table 15) 2 LCR[2] Stop bits. The length of stop bit is specified by this bit in conjunction with the programmed word length (see Table 16). 1:0 LCR[1:0] Word length bits 1, 0. These two bits specify the word length to be transmitted or received (see Table 17). logic 0 or cleared = default condition logic 0 or cleared = default condition Table 15. LCR[5:3] parity selection LCR[5] LCR[4] LCR[3] Parity selection X X 0 no parity X 0 1 odd parity 0 1 1 even parity 0 0 1 forced parity ‘1’ 1 1 1 forced parity ‘0’ SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 20 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 16. LCR[2] stop bit length LCR[2] Word length (bits) Stop bit length (bit times) 0 5, 6, 7, 8 1 1 5 11⁄2 1 6, 7, 8 2 Table 17. LCR[1:0] word length LCR[1] LCR[0] Word length (bits) 0 0 5 0 1 6 1 0 7 1 1 8 7.6 Modem Control Register (MCR) This register controls the interface with the modem or a peripheral device. Table 18. Modem Control Register bits description Bit Symbol Description 7:5 MCR[7:5] reserved; set to ‘0’ 4 MCR[4] Loopback. Enable the local Loopback mode (diagnostics). In this mode the transmitter output (TX) and the receiver input (RX), CTS, DSR, CD and RI are disconnected from the SC16C2550B I/O pins. Internally the modem data and control pins are connected into a loopback data configuration (see Figure 7). In this mode, the receiver and transmitter interrupts remain fully operational. The Modem Control Interrupts are also operational, but the interrupts’ sources are switched to the lower four bits of the Modem Control. Interrupts continue to be controlled by the IER register. logic 0 = disable Loopback mode (normal default condition) logic 1 = enable local Loopback mode (diagnostics) 3 MCR[3] OP2/INT enable logic 0 = forces INT (A, B) outputs to the 3-state mode and sets OP2 to a logic 1 (normal default condition) logic 1 = forces the INT (A, B outputs to the active mode and sets OP2 to a logic 0 2 MCR[2] (OP1). OP1A/OP1B are not available as an external signal in the SC16C2550B. This bit is instead used in the Loopback mode only. In the Loopback mode, this bit is used to write the state of the modem RI interface signal. 1 MCR[1] RTS logic 0 = force RTS output to a logic 1 (normal default condition) logic 1 = force RTS output to a logic 0 0 MCR[0] DTR logic 0 = force DTR output to a logic 1 (normal default condition) logic 1 = force DTR output to a logic 0 SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 21 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7.7 Line Status Register (LSR) This register provides the status of data transfers between the SC16C2550B and the CPU. Table 19. Line Status Register bits description Bit Symbol Description 7 LSR[7] FIFO data error. logic 0 = no error (normal default condition) logic 1 = at least one parity error, framing error or break indication is in the current FIFO data. This bit is cleared when there are no remaining error flags associated with the remaining data in the FIFO. 6 LSR[6] THR and TSR empty. This bit is the Transmit Empty indicator. This bit is set to a logic 1 whenever the Transmit Holding Register and the Transmit Shift Register are both empty. It is reset to logic 0 whenever either the THR or TSR contains a data character. In the FIFO mode, this bit is set to ‘1’ whenever the Transmit FIFO and Transmit Shift Register are both empty. 5 LSR[5] THR empty. This bit is the Transmit Holding Register Empty indicator. This bit indicates that the UART is ready to accept a new character for transmission. In addition, this bit causes the UART to issue an interrupt to CPU when the THR interrupt enable is set. The THR bit is set to a logic 1 when a character is transferred from the transmit holding register into the transmitter shift register. The bit is reset to a logic 0 concurrently with the loading of the transmitter holding register by the CPU. In the FIFO mode, this bit is set when the transmit FIFO is empty; it is cleared when at least 1 byte is written to the transmit FIFO. 4 LSR[4] Break interrupt. logic 0 = no break condition (normal default condition) logic 1 = the receiver received a break signal (RX was a logic 0 for one character frame time). In the FIFO mode, only one break character is loaded into the FIFO. 3 LSR[3] Framing error. logic 0 = no framing error (normal default condition) logic 1 = framing error. The receive character did not have a valid stop bit(s). In the FIFO mode, this error is associated with the character at the top of the FIFO. 2 LSR[2] Parity error. logic 0 = no parity error (normal default condition logic 1 = parity error. The receive character does not have correct parity information and is suspect. In the FIFO mode, this error is associated with the character at the top of the FIFO. 1 LSR[1] Overrun error. logic 0 = no overrun error (normal default condition) logic 1 = overrun error. A data overrun error occurred in the Receive Shift Register. This happens when additional data arrives while the FIFO is full. In this case, the previous data in the shift register is overwritten. Note that under this condition, the data byte in the Receive Shift Register is not transferred into the FIFO, therefore the data in the FIFO is not corrupted by the error. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 22 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 19. Line Status Register bits description …continued Bit Symbol Description 0 LSR[0] Receive data ready. logic 0 = no data in Receive Holding Register or FIFO (normal default condition) logic 1 = data has been received and is saved in the Receive Holding Register or FIFO 7.8 Modem Status Register (MSR) This register provides the current state of the control interface signals from the modem or other peripheral device to which the SC16C2550B is connected. Four bits of this register are used to indicate the changed information. These bits are set to a logic 1 whenever a control input from the modem changes state. These bits are set to a logic 0 whenever the CPU reads this register. Table 20. Modem Status Register bits description Bit Symbol Description 7 MSR[7] CD. During normal operation, this bit is the complement of the CD input. Reading this bit in the Loopback mode produces the state of MCR[3] (OP2). 6 MSR[6] RI. During normal operation, this bit is the complement of the RI input. Reading this bit in the Loopback mode produces the state of MCR[2] (OP1). 5 MSR[5] DSR. During normal operation, this bit is the complement of the DSR input. During the Loopback mode, this bit is equivalent to MCR[0] (DTR). 4 MSR[4] CTS. During normal operation, this bit is the complement of the CTS input. During the Loopback mode, this bit is equivalent to MCR[1] (RTS). 3 MSR[3] ∆CD [1] logic 0 = no CD change (normal default condition) logic 1 = the CD input to the SC16C2550B has changed state since the last time it was read. A modem Status Interrupt will be generated. 2 MSR[2] ∆RI [1] logic 0 = no RI change (normal default condition) logic 1 = the RI input to the SC16C2550B has changed from a logic 0 to a logic 1. A modem Status Interrupt will be generated. 1 MSR[1] ∆DSR [1] logic 0 = no DSR change (normal default condition) logic 1 = the DSR input to the SC16C2550B has changed state since the last time it was read. A modem Status Interrupt will be generated. 0 MSR[0] ∆CTS [1] logic 0 = no CTS change (normal default condition) logic 1 = the CTS input to the SC16C2550B has changed state since the last time it was read. A modem Status Interrupt will be generated. [1] Whenever any MSR bit 3:0 is set to logic 1, a Modem Status Interrupt will be generated. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 23 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7.9 Scratchpad Register (SPR) The SC16C2550B provides a temporary data register to store 8 bits of user information. 7.10 SC16C2550B external reset condition Table 21. Reset state for registers Register Reset state IER IER[7:0] = 0 FCR FCR[7:0] = 0 ISR ISR[7:1] = 0; ISR[0] = 1 LCR LCR[7:0] = 0 MCR MCR[7:0] = 0 LSR LSR[7] = 0; LSR[6:5] = 1; LSR[4:0] = 0 MSR MSR[7:4] = input signals; MSR[3:0] = 0 SPR SFR[7:0] = 1 DLL DLL[7:0] = X DLM DLM[7:0] = X Table 22. Reset state for outputs Output Reset state TXA, TXB logic 1 OP2A, OP2B logic 1 RTSA, RTSB logic 1 DTRA, DTRB logic 1 INTA, INTB 3-state condition SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 24 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 8. Limiting values Table 23. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter VCC supply voltage Vn voltage on any other pin Conditions Min Max Unit - 7 V at D7 to D0 pins GND − 0.3 VCC + 0.3 V at input only pins GND − 0.3 5.3 V Tamb operating temperature −40 +85 °C Tstg storage temperature −65 +150 °C Ptot/pack total power dissipation per package - 500 mW 9. Static characteristics Table 24. Static characteristics Tamb = −40 °C to +85 °C; tolerance of VCC ± 10 %; unless otherwise specified. Symbol Parameter VIL(clk) clock LOW-level input voltage Conditions VCC = 2.5 V VCC = 3.3 V VCC = 5.0 V Unit Min Max Min Max Min Max −0.3 +0.45 −0.3 +0.6 −0.5 +0.6 V VIH(clk) clock HIGH-level input voltage 1.8 VCC 2.4 VCC 3.0 VCC V VIL LOW-level input voltage except X1 clock −0.3 +0.65 −0.3 +0.8 −0.5 +0.8 V VIH HIGH-level input voltage except X1 clock 1.6 - 2.0 - 2.2 - V IOL = 5 mA (data bus) - - - - - 0.4 V IOL = 4 mA (other outputs) - - - 0.4 - - V IOL = 2 mA (data bus) - 0.4 - - - - V IOL = 1.6 mA (other outputs) - 0.4 - - - - V IOH = −5 mA (data bus) - - - - 2.4 - V IOH = −1 mA (other outputs) - - 2.0 - - - V IOH = −800 µA (data bus) 1.85 - - - - - V IOH = −400 µA (other outputs) 1.85 - - - - - V LOW-level output voltage VOL VOH HIGH-level output voltage on all outputs[1] ILIL LOW-level input leakage current - ±10 - ±10 - ±10 µA IL(clk) clock leakage current - ±30 - ±30 - ±30 µA ICC supply current - 3.5 - 4.5 - 4.5 mA Ci input capacitance - 5 - 5 - 5 pF [1] Except XTAL2, VOL = 1 V typical. f = 5 MHz SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 25 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 10. Dynamic characteristics Table 25. Dynamic characteristics Tamb = −40 °C to +85 °C; tolerance of VCC ± 10 %; unless otherwise specified. Symbol Parameter Conditions VCC = 2.5 V VCC = 3.3 V VCC = 5.0 V Min Max Min Max Min Max Unit tw1 clock pulse duration 10 - 6 - 6 - ns tw2 clock pulse duration 10 - 6 - 6 - ns - 48 - 80 0 - 0 - [1][2] fXTAL oscillator/clock frequency t6s address set-up time t6h address hold time 0 - 0 - 0 - ns t7d IOR delay from chip select 10 - 10 - 10 - ns t7w IOR strobe width 77 - 26 - 23 - ns t7h chip select hold time from IOR 0 - 0 - 0 - ns t9d read cycle delay 25 pF load 20 - 20 - 20 - ns t12d delay from IOR to data 25 pF load - 77 - 26 - 23 ns t12h data disable time 25 pF load - 15 - 15 - 15 ns 25 pF load 80 0 - MHz ns t13d IOW delay from chip select 10 - 10 - 10 - ns t13w IOW strobe width 20 - 20 - 15 - ns t13h chip select hold time from IOW 0 - 0 - 0 - ns t15d write cycle delay 25 - 25 - 20 - ns t16s data set-up time 20 - 20 - 15 - ns t16h data hold time 15 - 5 - 5 - ns t17d delay from IOW to output 25 pF load - 100 - 33 - 29 ns t18d delay to set interrupt from Modem input 25 pF load - 100 - 24 - 23 ns t19d delay to reset interrupt from 25 pF load IOR - 100 - 24 - 23 ns t20d delay from stop to set interrupt - TRCLK - TRCLK - TRCLK s t21d delay from IOR to reset interrupt - 100 - 29 - 28 ns t22d delay from start to set interrupt - 100 - 45 - 40 ns t23d delay from IOW to transmit start t24d delay from IOW to reset interrupt t25d delay from stop to set RXRDY t26d t27d [3] 25 pF load [3] 8TRCLK 24TRCLK 8TRCLK 24TRCLK 8TRCLK 24TRCLK s - 100 - 45 - 40 ns - TRCLK - TRCLK - TRCLK s delay from IOR to reset RXRDY - 100 - 45 - 40 ns delay from IOW to set TXRDY - 100 - 45 - 40 ns [3] SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 26 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 25. Dynamic characteristics …continued Tamb = −40 °C to +85 °C; tolerance of VCC ± 10 %; unless otherwise specified. Symbol Parameter Conditions VCC = 2.5 V t28d delay from start to reset TXRDY [3] tRESET RESET pulse width [4] N baud rate divisor VCC = 3.3 V VCC = 5.0 V Unit Min Max Min Max Min Max - 8TRCLK - 8TRCLK - 8TRCLK s 200 - 40 - 40 - ns (216 1 − 1) 1 (216 − 1) [1] Applies to external clock, crystal oscillator max 24 MHz. [2] Maximum frequency = ------- [3] RCLK is an internal signal derived from divisor latch LSB (DLL) and divisor latch MSB (DLM) divisor latches. [4] Reset pulse must happen when these signals are inactive: CS, IOW, IOR. 1 (216 − 1) 1 t w3 10.1 Timing diagrams t6h valid address A0 to A2 t13h t6s active CSA, CSB t13d IOW t15d t13w active t16s D0 to D7 t16h data 002aae279 Fig 8. General write timing SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 27 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs t6h valid address A0 to A2 t7h t6s active CSA, CSB t7d t9d t7w IOR active t12h t12d D0 to D7 data 002aae278 Fig 9. General read timing IOW active t17d RTSA, RTSB DTRA, DTRB change of state change of state CDA, CDB CTSA, CTSB DSRA, DSRB change of state t18d INTA, INTB change of state t18d active active active t19d IOR active active active t18d change of state RIA, RIB 002aae277 Fig 10. Modem input/output timing SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 28 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs tw2 tw1 EXTERNAL CLOCK 002aaa112 tw3 1 f XTAL = ------t w3 Fig 11. External clock timing start bit RXA, RXB parity bit data bits (0 to 7) D0 D1 D2 D3 D4 D5 D6 stop bit next data start bit D7 5 data bits 6 data bits 7 data bits t20d active INTA, INTB t21d active IOR 16 baud rate clock 002aae276 Fig 12. Receive timing SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 29 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs start bit D0 RXn parity bit data bits (0 to 7) D1 D2 D3 D4 D5 D6 stop bit next data start bit D7 t25d active data ready RXRDYn t26d active IOR 002aae275 Fig 13. Receive ready timing in non-FIFO mode start bit RXA, RXB parity bit data bits (0 to 7) D0 D1 D2 D3 D4 D5 D6 stop bit D7 first byte that reaches the trigger level t25d active data ready RXRDYA, RXRDYB t26d active IOR 002aae274 Fig 14. Receive ready timing in FIFO mode SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 30 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs start bit parity bit data bits (0 to 7) TXA, TXB D0 D1 D2 D3 D4 D5 D6 stop bit next data start bit D7 5 data bits 6 data bits 7 data bits active transmitter ready INTA, INTB t22d t24d t23d IOW active active 16 baud rate clock 002aae273 Fig 15. Transmit timing start bit TXA, TXB D0 IOW active D0 to D7 byte #1 parity bit data bits (0 to 7) D1 D2 D3 D4 D5 D6 stop bit next data start bit D7 t28d t27d active transmitter ready TXRDYA, TXRDYB transmitter not ready 002aae272 Fig 16. Transmit ready timing in non-FIFO mode SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 31 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs start bit data bits (0 to 7) D0 TXA, TXB parity bit D1 D2 D3 D4 D5 D6 stop bit D7 5 data bits 6 data bits 7 data bits IOW active t28d D0 to D7 byte #16 t27d TXRDYA, TXRDYB FIFO full 002aae271 Fig 17. Transmit ready timing in FIFO mode (DMA mode ‘1’) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 32 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 11. Package outline PLCC44: plastic leaded chip carrier; 44 leads SOT187-2 eD eE y X 39 A 29 28 40 bp ZE b1 w M 44 1 E HE pin 1 index A A4 A1 e (A 3) 6 β 18 Lp k 7 detail X 17 e v M A ZD D B HD v M B 0 5 10 mm scale DIMENSIONS (mm dimensions are derived from the original inch dimensions) A4 A1 e UNIT A A3 D(1) E(1) eD eE HD bp b1 max. min. 4.57 4.19 mm inches 0.81 0.66 HE k 16.66 16.66 16.00 16.00 17.65 17.65 1.22 1.27 16.51 16.51 14.99 14.99 17.40 17.40 1.07 0.51 0.25 3.05 0.53 0.33 0.180 0.02 0.165 0.01 0.12 0.021 0.032 0.656 0.656 0.05 0.013 0.026 0.650 0.650 0.63 0.59 0.63 0.59 Lp v w y 1.44 1.02 0.18 0.18 0.1 ZD(1) ZE(1) max. max. 2.16 β 2.16 45 o 0.695 0.695 0.048 0.057 0.007 0.007 0.004 0.085 0.085 0.685 0.685 0.042 0.040 Note 1. Plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC JEITA SOT187-2 112E10 MS-018 EDR-7319 EUROPEAN PROJECTION ISSUE DATE 99-12-27 01-11-14 Fig 18. Package outline SOT187-2 (PLCC44) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 33 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs HVQFN32: plastic thermal enhanced very thin quad flat package; no leads; 32 terminals; body 5 x 5 x 0.85 mm A B D SOT617-1 terminal 1 index area A A1 E c detail X C e1 e 1/2 e 16 y y1 C v M C A B w M C b 9 L 17 8 e e2 Eh 1/2 e 1 terminal 1 index area 24 32 25 X Dh 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT A(1) max. A1 b c D (1) Dh E (1) Eh e e1 e2 L v w y y1 mm 1 0.05 0.00 0.30 0.18 0.2 5.1 4.9 3.25 2.95 5.1 4.9 3.25 2.95 0.5 3.5 3.5 0.5 0.3 0.1 0.05 0.05 0.1 Note 1. Plastic or metal protrusions of 0.075 mm maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC JEITA SOT617-1 --- MO-220 --- EUROPEAN PROJECTION ISSUE DATE 01-08-08 02-10-18 Fig 19. Package outline SOT617-1 (HVQFN32) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 34 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs LQFP48: plastic low profile quad flat package; 48 leads; body 7 x 7 x 1.4 mm SOT313-2 c y X 36 25 A 37 24 ZE e E HE A A2 (A 3) A1 w M θ bp pin 1 index Lp L 13 48 1 detail X 12 ZD e v M A w M bp D B HD v M B 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT A max. A1 A2 A3 bp c D (1) E (1) e HD HE L Lp v w y mm 1.6 0.20 0.05 1.45 1.35 0.25 0.27 0.17 0.18 0.12 7.1 6.9 7.1 6.9 0.5 9.15 8.85 9.15 8.85 1 0.75 0.45 0.2 0.12 0.1 Z D (1) Z E (1) θ 0.95 0.55 7 o 0 0.95 0.55 o Note 1. Plastic or metal protrusions of 0.25 mm maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC SOT313-2 136E05 MS-026 JEITA EUROPEAN PROJECTION ISSUE DATE 00-01-19 03-02-25 Fig 20. Package outline SOT313-2 (LQFP48) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 35 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs seating plane DIP40: plastic dual in-line package; 40 leads (600 mil) SOT129-1 ME D A2 L A A1 c e Z w M b1 (e 1) b MH 21 40 pin 1 index E 1 20 0 5 10 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT A max. A1 min. A2 max. b b1 c mm 4.7 0.51 4 1.70 1.14 0.53 0.38 0.36 0.23 52.5 51.5 inches 0.19 0.02 0.16 0.067 0.045 0.021 0.015 0.014 0.009 2.067 2.028 D e e1 L ME MH w Z (1) max. 14.1 13.7 2.54 15.24 3.60 3.05 15.80 15.24 17.42 15.90 0.254 2.25 0.56 0.54 0.1 0.6 0.14 0.12 0.62 0.60 0.69 0.63 0.01 0.089 (1) E (1) Note 1. Plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC JEITA SOT129-1 051G08 MO-015 SC-511-40 EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-13 Fig 21. Package outline SOT129-1 (DIP40) SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 36 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 12. Soldering of SMD packages This text provides a very brief insight into a complex technology. A more in-depth account of soldering ICs can be found in Application Note AN10365 “Surface mount reflow soldering description”. 12.1 Introduction to soldering Soldering is one of the most common methods through which packages are attached to Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both the mechanical and the electrical connection. There is no single soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization. 12.2 Wave and reflow soldering Wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. The wave soldering process is suitable for the following: • Through-hole components • Leaded or leadless SMDs, which are glued to the surface of the printed circuit board Not all SMDs can be wave soldered. Packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. Also, leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased probability of bridging. The reflow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature profile. Leaded packages, packages with solder balls, and leadless packages are all reflow solderable. Key characteristics in both wave and reflow soldering are: • • • • • • Board specifications, including the board finish, solder masks and vias Package footprints, including solder thieves and orientation The moisture sensitivity level of the packages Package placement Inspection and repair Lead-free soldering versus SnPb soldering 12.3 Wave soldering Key characteristics in wave soldering are: • Process issues, such as application of adhesive and flux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave • Solder bath specifications, including temperature and impurities SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 37 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 12.4 Reflow soldering Key characteristics in reflow soldering are: • Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to higher minimum peak temperatures (see Figure 22) than a SnPb process, thus reducing the process window • Solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board • Reflow temperature profile; this profile includes preheat, reflow (in which the board is heated to the peak temperature) and cooling down. It is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic). In addition, the peak temperature must be low enough that the packages and/or boards are not damaged. The peak temperature of the package depends on package thickness and volume and is classified in accordance with Table 26 and 27 Table 26. SnPb eutectic process (from J-STD-020C) Package thickness (mm) Package reflow temperature (°C) Volume (mm3) < 350 ≥ 350 < 2.5 235 220 ≥ 2.5 220 220 Table 27. Lead-free process (from J-STD-020C) Package thickness (mm) Package reflow temperature (°C) Volume (mm3) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245 Moisture sensitivity precautions, as indicated on the packing, must be respected at all times. Studies have shown that small packages reach higher temperatures during reflow soldering, see Figure 22. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 38 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs maximum peak temperature = MSL limit, damage level temperature minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 22. Temperature profiles for large and small components For further information on temperature profiles, refer to Application Note AN10365 “Surface mount reflow soldering description”. 13. Soldering of through-hole mount packages 13.1 Introduction to soldering through-hole mount packages This text gives a very brief insight into wave, dip and manual soldering. Wave soldering is the preferred method for mounting of through-hole mount IC packages on a printed-circuit board. 13.2 Soldering by dipping or by solder wave Driven by legislation and environmental forces the worldwide use of lead-free solder pastes is increasing. Typical dwell time of the leads in the wave ranges from 3 seconds to 4 seconds at 250 °C or 265 °C, depending on solder material applied, SnPb or Pb-free respectively. The total contact time of successive solder waves must not exceed 5 seconds. The device may be mounted up to the seating plane, but the temperature of the plastic body must not exceed the specified maximum storage temperature (Tstg(max)). If the printed-circuit board has been pre-heated, forced cooling may be necessary immediately after soldering to keep the temperature within the permissible limit. 13.3 Manual soldering Apply the soldering iron (24 V or less) to the lead(s) of the package, either below the seating plane or not more than 2 mm above it. If the temperature of the soldering iron bit is less than 300 °C it may remain in contact for up to 10 seconds. If the bit temperature is between 300 °C and 400 °C, contact may be up to 5 seconds. SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 39 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 13.4 Package related soldering information Table 28. Suitability of through-hole mount IC packages for dipping and wave soldering Package Soldering method Dipping Wave CPGA, HCPGA - suitable DBS, DIP, HDIP, RDBS, SDIP, SIL suitable suitable[1] PMFP[2] - not suitable [1] For SDIP packages, the longitudinal axis must be parallel to the transport direction of the printed-circuit board. [2] For PMFP packages hot bar soldering or manual soldering is suitable. 14. Abbreviations Table 29. Abbreviations Acronym Description CPU Central Processing Unit DLL Divisor Latch LSB DLM Divisor Latch MSB DMA Direct Memory Access FIFO First In/First Out ISDN Integrated Service Digital Network LSB Least Significant Bit MSB Most Significant Bit RHR Receive Holding Register THR Transmit Holding Register TTL Transistor-Transistor Logic UART Universal Asynchronous Receiver/Transmitter SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 40 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 15. Revision history Table 30. Revision history Document ID Release date Data sheet status Change notice Supersedes SC16C2550B_5 20090112 Product data sheet - SC16C2550B_4 Modifications: • Section 2 “Features”: bullet item changed from “5 V tolerant inputs” to “5 V tolerant on input only pins” and added Footnote 1. • Figure 7 “Internal Loopback mode diagram”: 3rd – at signals coming out of ‘modem control logic’ block, changed from “OP1A, OP2B” to “OP1A, OP1B” • Table 23 “Limiting values”: – symbol Vn split to show 2 separate conditions: “at D7 to D0 pins” and “at input only pins” • Table 24 “Static characteristics”: – changed symbol/parameter from “VIL(CK), LOW-level clock input voltage” to “VIL(clk), clock LOW-level input voltage” – changed symbol/parameter from “VIH(CK), HIGH-level clock input voltage” to “VIH(clk), clock HIGH-level input voltage” – changed symbol/parameter from “ICL, clock leakage” to “IL(clk), clock leakage current” • • Table 25 “Dynamic characteristics”: added Table note [4] and its reference at tRESET updated soldering information SC16C2550B_4 20070215 Product data sheet - SC16C2550B_3 SC16C2550B_3 20050926 Product data sheet - SC16C2550B-02 SC16C2550B-02 (9397 750 14449) 20041214 Product data - SC16C2550B-01 SC16C2550B-01 (9397 750 11982) 20050719 Product data - - SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 41 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 16. Legal information 16.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term ‘short data sheet’ is explained in section “Definitions”. [3] The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL http://www.nxp.com. 16.2 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. Short data sheet — A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail. 16.3 Disclaimers General — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof. Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) may cause permanent damage to the device. Limiting values are stress ratings only and operation of the device at these or any other conditions above those given in the Characteristics sections of this document is not implied. Exposure to limiting values for extended periods may affect device reliability. Terms and conditions of sale — NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms, including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by NXP Semiconductors. In case of any inconsistency or conflict between information in this document and such terms and conditions, the latter will prevail. No offer to sell or license — Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights. 16.4 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. 17. Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com SC16C2550B_5 Product data sheet © NXP B.V. 2009. All rights reserved. Rev. 05 — 12 January 2009 42 of 43 SC16C2550B NXP Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 18. Contents 1 2 3 3.1 4 5 5.1 5.2 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 7 7.1 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pinning information . . . . . . . . . . . . . . . . . . . . . . 4 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 6 Functional description . . . . . . . . . . . . . . . . . . . 9 UART A-B functions . . . . . . . . . . . . . . . . . . . . . 9 Internal registers. . . . . . . . . . . . . . . . . . . . . . . 10 FIFO operation . . . . . . . . . . . . . . . . . . . . . . . . 11 Hardware/software and time-out interrupts. . . 11 Programmable baud rate generator . . . . . . . . 12 DMA operation . . . . . . . . . . . . . . . . . . . . . . . . 13 Loopback mode . . . . . . . . . . . . . . . . . . . . . . . 13 Register descriptions . . . . . . . . . . . . . . . . . . . 15 Transmit Holding Register (THR) and Receive Holding Register (RHR) . . . . . . . . . . . . . . . . . 15 7.2 Interrupt Enable Register (IER) . . . . . . . . . . . 16 7.2.1 IER versus Transmit/Receive FIFO interrupt mode operation. . . . . . . . . . . . . . . . . . . . . . . . 17 7.2.2 IER versus Receive/Transmit FIFO polled mode operation. . . . . . . . . . . . . . . . . . . . . . . . 17 7.3 FIFO Control Register (FCR) . . . . . . . . . . . . . 17 7.3.1 DMA mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 7.3.1.1 Mode 0 (FCR bit 3 = 0) . . . . . . . . . . . . . . . . . . 17 7.3.1.2 Mode 1 (FCR bit 3 = 1) . . . . . . . . . . . . . . . . . . 17 7.3.2 FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7.4 Interrupt Status Register (ISR) . . . . . . . . . . . . 19 7.5 Line Control Register (LCR) . . . . . . . . . . . . . . 20 7.6 Modem Control Register (MCR) . . . . . . . . . . . 21 7.7 Line Status Register (LSR) . . . . . . . . . . . . . . . 22 7.8 Modem Status Register (MSR). . . . . . . . . . . . 23 7.9 Scratchpad Register (SPR) . . . . . . . . . . . . . . 24 7.10 SC16C2550B external reset condition . . . . . . 24 8 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 25 9 Static characteristics. . . . . . . . . . . . . . . . . . . . 25 10 Dynamic characteristics . . . . . . . . . . . . . . . . . 26 10.1 Timing diagrams . . . . . . . . . . . . . . . . . . . . . . . 27 11 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 33 12 Soldering of SMD packages . . . . . . . . . . . . . . 37 12.1 Introduction to soldering . . . . . . . . . . . . . . . . . 37 12.2 Wave and reflow soldering . . . . . . . . . . . . . . . 37 12.3 Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 37 12.4 13 13.1 13.2 13.3 13.4 14 15 16 16.1 16.2 16.3 16.4 17 18 Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . Soldering of through-hole mount packages . Introduction to soldering through-hole mount packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . Soldering by dipping or by solder wave . . . . . Manual soldering . . . . . . . . . . . . . . . . . . . . . . Package related soldering information . . . . . . Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . Revision history . . . . . . . . . . . . . . . . . . . . . . . Legal information . . . . . . . . . . . . . . . . . . . . . . Data sheet status . . . . . . . . . . . . . . . . . . . . . . Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . Contact information . . . . . . . . . . . . . . . . . . . . Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 39 39 39 39 40 40 41 42 42 42 42 42 42 43 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2009. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com Date of release: 12 January 2009 Document identifier: SC16C2550B_5