SC16C2550B 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Rev. 01 — 29 March 2004 Product data 1. 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 TXRDY and RXRDY 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 loop-back 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 and DIP40 packages. 2. Features ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 2 channel UART 5 V, 3.3 V and 2.5 V operation 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 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs ■ Fully programmable character formatting: ◆ 5, 6, 7, or 8-bit characters ◆ Even, Odd, or No-Parity formats ◆ 1, 11⁄2, or 2-stop bit ◆ Baud generation (DC to 5 Mbit/s) ■ False start-bit detection ■ Complete status reporting capabilities ■ 3-State output TTL drive capabilities for bi-directional data bus and control bus ■ Line Break generation and detection ■ Internal diagnostic capabilities: ◆ Loop-back controls for communications link fault isolation ■ Prioritized interrupt system controls ■ Modem control functions (CTS, RTS, DSR, DTR, RI, DCD). 3. Ordering information Table 1: Ordering information Type number Package Name Description Version SC16C2550BIN40 DIP40 plastic dual in-line package; 40 leads (600 mil) SOT129-1 SC16C2550BIA44 PLCC44 plastic leaded chip carrier; 44 leads SOT187-2 SC16C2550BIB48 LQFP48 plastic low profile quad flat package; 48 leads; body 7 × 7 × 1.4 mm SOT313-2 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 2 of 42 SC16C2550B Philips 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–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–D7 IOR IOW RESET TRANSMIT FIFO REGISTER DTRA, DTRB RTSA, RTSB OP2A, OP2B MODEM CONTROL LOGIC INTA, INTB TXRDYA, TXRDYB RXRDYA, RXRDYB INTERRUPT CONTROL LOGIC CTSA, CTSB RIA, RIB CDA, CDB DSRA, DSRB CLOCK AND BAUD RATE GENERATOR 002aaa595 XTAL1 XTAL2 Fig 1. SC16C2550B block diagram. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 3 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 5. Pinning information 5.1 Pinning 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 RXA 10 TXA 11 TXB 12 SC16C2550BIN40 D0 1 32 RTSA 31 OP2A 30 INTA 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 2. DIP40 pin configuration. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 4 of 42 SC16C2550B Philips Semiconductors 40 CTSA 41 DSRA 42 CDA 43 RIA 44 VCC 1 TXRDYA 2 D0 3 D1 4 D2 5 D3 6 D4 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 34 RXRDYA TXA 13 33 INTA TXB 14 32 INTB CTSB 28 RTSB 27 RIB 26 DSRB 25 IOR 24 RXRDYB 23 29 A2 GND 22 CSB 17 CDB 21 30 A1 IOW 20 CSA 16 XTAL2 19 31 A0 XTAL1 18 OP2B 15 002aaa597 Fig 3. PLCC44 pin configuration. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 5 of 42 SC16C2550B Philips Semiconductors 37 N.C. 38 CTSA 39 DSRA 40 CDA 41 RIA 42 VCC 43 TXRDYA 44 D0 45 D1 46 D2 47 D3 48 D4 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs D5 1 36 RESET D6 2 35 DTRB D7 3 34 DTRA RXB 4 33 RTSA RXA 5 32 OP2A TXRDYB 6 31 RXRDYA SC16C2550BIB48 26 A2 N.C. 12 25 N.C. N.C. 24 CSB 11 CTSB 23 27 A1 RTSB 22 CSA 10 RIB 21 28 A0 DSRB 20 9 IOR 19 OP2B RXRDYB 18 29 INTB GND 17 8 CDB 16 TXB IOW 15 30 INTA XTAL2 14 7 XTAL1 13 TXA 002aaa598 Fig 4. LQFP48 pin configuration. 5.2 Pin description Table 2: Pin description Symbol Pin Type Description DIP40 PLCC44 LQFP48 A0 28 31 28 I Address 0 select bit. Internal register address selection. A1 27 30 27 I Address 1 select bit. Internal register address selection. A2 26 29 26 I Address 2 select bit. Internal register address selection. CSA, CSB 14, 15 16, 17 10, 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-D7 1-8 2-9 44-48, 1-3 I/O Data bus (bi-directional). 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. GND 20 22 17 I Signal and power ground. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 6 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 2: Pin description…continued Symbol Pin Type Description DIP40 PLCC44 LQFP48 INTA, INTB 30, 29 33, 32 30, 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 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-A2 onto the SC16C2550B data bus (D0-D7) for access by external CPU. IOW 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-D7) from the external CPU to an internal register that is defined by address bits A0-A2. OP2A, OP2B 31, 13 35, 15 32, 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 bit 3, Modem Control Register (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. RESET 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, RXRDYB - 34, 23 31, 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, i.e., 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, TXRDYB - 1, 12 43, 6 O 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, i.e., at lease 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). VCC 40 44 42 I Power supply input. XTAL1 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 5. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 7 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 2: Pin description…continued Symbol Pin Type Description DIP40 PLCC44 LQFP48 XTAL2 17 CDA, CDB 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. 38, 19 42, 21 40, 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, CTSB 36, 25 40, 28 38, 23 I Clear to Send (Active-LOW). These inputs are associated with individual UART channels, A through B. A logic 0 on the CTS 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. DSRA, DSRB 37, 22 41, 25 39, 20 I 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. DTRA, DTRB 33, 34 37, 38 34, 35 O 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 DTR 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. RIA, RIB 39, 23 43, 26 41, 21 I 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. RTSA, RTSB 32, 24 36, 27 33, 22 O Request to Send (Active-LOW). These outputs are associated with individual UART channels, A through B. A logic 0 on the RTS 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. 11, 10 5, 4 I Receive data A, B. These inputs are associated with individual serial channel data to the SC16C2550B receive input circuits, A-B. The RX signal will be a logic 1 during reset, idle (no data), or when the transmitter is disabled. During the local loop-back mode, the RX input pin is disabled and TX data is connected to the UART RX input, internally. TXA, TXB 11, 12 13, 14 7, 8 O Transmit data A, B. These outputs are associated with individual serial transmit channel data from the SC16C2550B. The TX signal will be a logic 1 during reset, idle (no data), or when the transmitter is disabled. During the local loop-back mode, the TX output pin is disabled and TX data is internally connected to the UART RX input. RXA, RXB 10, 9 19 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 8 of 42 SC16C2550B Philips 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 is 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 bi-directionally 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-B. Individual channel select functions are shown in Table 3. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 9 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 3: 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 4. 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 4: A2 Internal registers decoding A1 A0 READ mode WRITE mode General register set (THR/RHR, IER/ISR, MCR/MSR, FCR, 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] [2] These registers are accessible only when LCR[7] is a logic 0. These registers are accessible only when LCR[7] is a logic 1. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 10 of 42 SC16C2550B Philips 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 6-7, 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 5: Flow control mechanism Selected trigger level (characters) INT pin activation 1 1 4 4 8 8 14 14 6.4 Hardware/software and time-out interrupts The interrupts are enabled by IER[0-3]. 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, i.e., 1×, 1.5×, or 2× bit times. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 11 of 42 SC16C2550B Philips 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 6). 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. X1 1.8432 MHz C1 22 pF XTAL2 XTAL1 XTAL2 XTAL1 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 6 shows the selectable baud rate table available when using a 1.8432 MHz external clock input. X1 1.8432 MHz C2 33 pF C1 22 pF 1.5 kΩ C2 47 pF 002aaa586 Fig 5. Crystal oscillator connection. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 12 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 6: Baud rate generator programming table using a 1.8432 MHz clock Output baud rate Output Output DLM 16 × clock divisor 16 × clock divisor program value (decimal) (HEX) (HEX) DLL program value (HEX) 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[5,6] 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 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 TXRDY (or RXRDY) 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 Loop-back mode The internal loop-back capability allows on-board diagnostics. In the loop-back mode, the normal modem interface pins are disconnected and reconfigured for loop-back internally (see Figure 6). MCR[0-3] register bits are used for controlling loop-back diagnostic testing. In the loop-back 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 inputs pins, and instead are connected internally to RTS, DTR, MCR[3] (OP2) and MCR[2] (OP1). Loop-back test data is entered into the transmit holding register via the user data bus interface, D0-D7. The transmit UART serializes the data and passes the serial data to the receive UART via the internal loop-back connection. The receive UART converts the serial data back into parallel © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 13 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs data that is then made available at the user data interface D0-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 TRANSMIT FIFO REGISTER D0–D7 IOR IOW RESET TRANSMIT SHIFT REGISTER TXA, TXB DATA BUS AND CONTROL LOGIC A0–A2 CSA, CSB REGISTER SELECT LOGIC INTERCONNECT BUS LINES AND CONTROL SIGNALS MCR[4] = 1 RECEIVE FIFO REGISTER RECEIVE SHIFT REGISTER RXA, RXB RTSA, RTSB CTSA, CTSB DTRA, DTRB MODEM CONTROL LOGIC DSRA, DSRB (OP1A, OP1B) INTA, INTB TXRDYA, TXRDYB RXRDYA, RXRDYB INTERRUPT CONTROL LOGIC RIA, RIB CLOCK AND BAUD RATE GENERATOR (OP2A, OP2B) CDA, CDB 002aaa599 XTAL1 XTAL2 Fig 6. Internal loop-back mode diagram. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 14 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7. Register descriptions Table 7 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 7: 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 Set[2] 0 0 0 RHR XX bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 0 0 THR XX bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 0 1 IER 00 0 0 0 0 modem receive status line interrupt status interrupt transmit holding register interrupt receive holding register 0 1 0 FCR 00 RCVR trigger (MSB) RCVR trigger (LSB) reserved 0 reserved 0 DMA mode select XMIT FIFO reset RCVR FIFO reset FIFOs enable 0 1 0 ISR 01 FIFOs enabled FIFOs enabled 0 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 1 0 1 LSR 60 FIFO data error 1 1 0 MSR X0 1 1 1 SPR Special Register word length bit 0 loop back OP2/INT (OP1) enable RTS DTR THR and THR TSR empty empty break interrupt framing error parity error overrun error receive data ready CD RI DSR CTS ∆CD ∆RI ∆DSR ∆CTS FF bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 0 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] [2] [3] The value shown in represents the register’s initialized HEX value; X = n/a. Accessible only when LCR[7] is logic 0. Baud rate registers accessible only when LCR[7] is logic 1. 7.1 Transmit (THR) and Receive (RHR) Holding Registers 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-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). © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 15 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 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 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 7-1⁄2 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 8: 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[0-3]. 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[1-4]. 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. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 16 of 42 SC16C2550B Philips 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[0-3] 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[1-4] 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 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 (TXRDY) on PLCC44 and LQFP48 packages will go to a logic 0 whenever the FIFO (THR, if FIFO is not enabled) is empty. Receive Ready (RXRDY) on PLCC44 and LQFP48 packages will go to a logic 0 whenever the Receive Holding Register (RHR) is loaded with a character. 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. TXRDY on PLCC 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 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 17 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs level. However, the FIFO continues to fill 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 9: 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 10. 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 TXRDY pin in PLCC44 or LQFP48 packages will be a logic 0. Once active, the TXRDY 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 lease one character in the receive FIFO, the RXRDY pin will be a logic 0. Once active, the RXRDY 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 TXRDY 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 RXRDY 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. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 18 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 9: 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 10: 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 11 “Interrupt source” shows the data values (bits 0-3) for the four prioritized interrupt levels and the interrupt sources associated with each of these interrupt levels. Table 11: 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) © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 19 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 12: 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 11). Logic 0 or cleared = default condition. 0 ISR[0] INT status. 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 13: Line Control Register bits description Bit Symbol Description 7 LCR[7] Divisor latch enable. The internal baud rate counter latch and Enhance 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 14). 2 LCR[2] Stop bits. The length of stop bit is specified by this bit in conjunction with the programmed word length (see Table 15). Logic 0 or cleared = default condition. 1-0 LCR[1-0] Word length bits 1, 0. These two bits specify the word length to be transmitted or received (see Table 16). Logic 0 or cleared = default condition. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 20 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 14: 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’ Table 15: LCR[2] stop bit length LCR[2] Word length 0 5, 6, 7, 8 1 1 5 1-1⁄2 1 6, 7, 8 2 Table 16: Stop bit length (bit times) LCR[1-0] word length LCR[1] LCR[0] Word length 0 0 5 0 1 6 1 0 7 1 1 8 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 21 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 7.6 Modem Control Register (MCR) This register controls the interface with the modem or a peripheral device. Table 17: Modem Control Register bits description Bit Symbol Description 7-5 MCR[7-5] Reserved; set to ‘0’. 4 MCR[4] Loop-back. Enable the local loop-back 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 loop-back data configuration (see Figure 6). 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 loop-back mode (normal default condition). Logic 1 = Enable local loop-back 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 Loop-back mode only. In the loop-back 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. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 22 of 42 SC16C2550B Philips 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 18: 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. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 23 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 18: Line Status Register bits description…continued Bit Symbol Description 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. 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 19: 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 loop-back 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 loop-back 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 loop-back 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 loop-back 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. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 24 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Table 19: Modem Status Register bits description…continued Bit Symbol Description 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 0-3 is set to logic 1, a Modem Status Interrupt will be generated. 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 20: 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 21: 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 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 25 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 8. Limiting values Table 22: Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter VCC supply voltage Vn Tamb Conditions Min Max Unit - 7 V voltage at any pin GND − 0.3 VCC + 0.3 V operating temperature −40 +85 °C Tstg storage temperature −65 +150 °C Ptot(pack) total power dissipation per package - 500 mW 9. Static characteristics Table 23: DC electrical characteristics Tamb = −40 °C to +85 °C; VCC = 2.5 V, 3.3 V or 5.0 V ±10%, unless otherwise specified. Symbol Parameter Conditions 2.5 V 3.3 V 5.0 V Min Max Min Max Min Max Unit VIL(CK) LOW-level clock input voltage −0.3 0.45 −0.3 0.6 −0.5 0.6 V VIH(CK) HIGH-level clock 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 VOL LOW-level output voltage on all outputs[1] IOL = 5 mA (databus) - - - - - 0.4 V IOL = 4 mA (other outputs) - - - 0.4 - - V IOL = 2 mA (databus) - 0.4 - - - - V IOL = 1.6 mA (other outputs) - 0.4 - - - - V IOH = −5 mA (databus) - - - - 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 - ±10 - ±10 - ±10 µA - ±30 - ±30 - ±30 µA - 3.5 - 4.5 - 4.5 mA - 5 - 5 - 5 pF VOH HIGH-level output voltage ILIL LOW-level input leakage current ICL clock leakage ICC supply current Ci input capacitance [1] f = 5 MHz Except x2, VOL = 1 V typical. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 26 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 10. Dynamic characteristics Table 24: AC electrical characteristics Tamb = −40 °C to +85 °C; VCC = 2.5 V, 3.3 V or 5.0 V ±10%, unless otherwise specified. Symbol Parameter Conditions 2.5 V 3.3 V 5.0 V Unit Min Max Min Max Min Max 10 - 6 - 6 - ns - 48 - 80 80 MHz t1w, t2w clock pulse duration t3w oscillator/clock frequency t6s address set-up time 0 - 0 - 0 - ns 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 [1] 25 pF load t12d delay from IOR to data 25 pF load - 77 - 26 - 23 ns t12h data disable time 25 pF load - 15 - 15 - 15 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 IOR 25 pF load - 100 - 24 - 23 ns - 1 - 1 - 1 Rclk 25 pF load - 100 - 29 - 28 ns t20d delay from stop to set interrupt t21d delay from IOR to reset interrupt t22d delay from start to set interrupt - 100 - 45 - 40 ns t23d delay from IOW to transmit start 8 24 8 24 8 24 Rclk t24d delay from IOW to reset interrupt - 100 - 45 - 40 ns t25d delay from stop to set RXRDY - 1 - 1 - 1 Rclk t26d delay from IOR to reset RXRDY - 100 - 45 - 40 ns t27d delay from IOW to set TXRDY - 100 - 45 - 40 ns t28d delay from start to reset TXRDY - 8 - 8 - 8 Rclk tRESET Reset pulse width 200 - 40 - 40 - ns N baud rate divisor 1 216 − 1 1 216 − 1 1 216 − 1 Rclk [1] Applies to external clock, crystal oscillator max 24 MHz. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 27 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 10.1 Timing diagrams t6h VALID ADDRESS A0–A2 t6s t13h ACTIVE CSx t13d t15d t13w IOW ACTIVE t16s D0–D7 t16h DATA 002aaa109 Fig 7. General write timing. t6h VALID ADDRESS A0–A2 t6s t7h ACTIVE CSx t7d t9d t7w IOR ACTIVE t12h t12d D0–D7 DATA 002aaa110 Fig 8. General read timing. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 28 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs IOW ACTIVE t17d RTS DTR CHANGE OF STATE CHANGE OF STATE DCD CHANGE OF STATE CTS CHANGE OF STATE DSR t18d INT t18d ACTIVE ACTIVE ACTIVE t19d IOR ACTIVE ACTIVE ACTIVE t18d RI CHANGE OF STATE 002aaa111 Fig 9. Modem input/output timing. t 2w t 1w EXTERNAL CLOCK 002aaa112 t 3w Fig 10. External clock timing. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 29 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs PARITY BIT START BIT STOP BIT NEXT DATA START BIT DATA BITS (5-8) RX D0 D1 D2 D3 D4 D5 D6 D7 5 DATA BITS 6 DATA BITS t20d 7 DATA BITS ACTIVE INT t21d ACTIVE IOR 16 BAUD RATE CLOCK 002aaa113 Fig 11. Receive timing. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 30 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs START BIT PARITY BIT STOP BIT NEXT DATA START BIT DATA BITS (5–8) RX D0 D1 D2 D3 D4 D5 D6 D7 t25d ACTIVE DATA READY RXRDY t26d ACTIVE IOR 002aaa578 Fig 12. Receive ready timing in non-FIFO mode. START BIT PARITY BIT STOP BIT DATA BITS (5–8) RX D0 D1 D2 D3 D4 D5 D6 D7 FIRST BYTE THAT REACHES THE TRIGGER LEVEL t25d ACTIVE DATA READY RXRDY t26d ACTIVE IOR 002aaa579 Fig 13. Receive ready timing in FIFO mode. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 31 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs PARITY BIT START BIT STOP BIT NEXT DATA START BIT DATA BITS (5–8) TX D0 D1 D2 D3 D4 D5 D6 D7 5 DATA BITS 6 DATA BITS 7 DATA BITS ACTIVE TX READY INT t22d t24d t23d IOW ACTIVE ACTIVE 16 BAUD RATE CLOCK 002aaa116 Fig 14. Transmit timing. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 32 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs START BIT PARITY BIT STOP BIT NEXT DATA START BIT DATA BITS (5-8) TX IOW D0-D7 D0 D1 D2 D3 D4 D5 D6 D7 ACTIVE BYTE #1 t28d t27d ACTIVE TRANSMITTER READY TXRDY TRANSMITTER NOT READY 002aaa580 Fig 15. Transmit ready timing in non-FIFO mode. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 33 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs START BIT PARITY BIT STOP BIT DATA BITS (5-8) TX D0 D1 D2 D3 D4 D5 D6 D7 5 DATA BITS 6 DATA BITS 7 DATA BITS IOW ACTIVE t28d D0–D7 BYTE #16 t27d TXRDY FIFO FULL 002aaa581 Fig 16. Transmit ready timing in FIFO mode (DMA mode ‘1’). © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 34 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 11. Package outline 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 17. DIP40 package outline (SOT129-1). © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 35 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 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 UNIT A A3 D(1) E(1) e 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. PLCC44 package outline (SOT187-2). © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 36 of 42 SC16C2550B Philips 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 detail X 12 1 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 0o 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 19. LQFP48 package outline (SOT313-2). © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 37 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 12. Soldering 12.1 Introduction This text gives a very brief insight to a complex technology. A more in-depth account of soldering ICs can be found in our Data Handbook IC26; Integrated Circuit Packages (document order number 9398 652 90011). There is no soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and surface mount components are mixed on one printed-circuit board. Wave soldering can still be used for certain surface mount ICs, but it is not suitable for fine pitch SMDs. In these situations reflow soldering is recommended. Driven by legislation and environmental forces the worldwide use of lead-free solder pastes is increasing. 12.2 Through-hole mount packages 12.2.1 Soldering by dipping or by solder wave Typical dwell time of the leads in the wave ranges from 3 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. 12.2.2 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 and 400 °C, contact may be up to 5 seconds. 12.3 Surface mount packages 12.3.1 Reflow soldering Reflow soldering requires solder paste (a suspension of fine solder particles, flux and binding agent) to be applied to the printed-circuit board by screen printing, stencilling or pressure-syringe dispensing before package placement. Several methods exist for reflowing; for example, convection or convection/infrared heating in a conveyor type oven. Throughput times (preheating, soldering and cooling) vary between 100 and 200 seconds depending on heating method. Typical reflow peak temperatures range from 215 to 270 °C depending on solder paste material. The top-surface temperature of the packages should preferably be kept: • below 225 °C (SnPb process) or below 245 °C (Pb-free process) – for all the BGA and SSOP-T packages © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 38 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs – for packages with a thickness ≥ 2.5 mm – for packages with a thickness < 2.5 mm and a volume ≥ 350 mm3 so called thick/large packages. • below 240 °C (SnPb process) or below 260 °C (Pb-free process) for packages with a thickness < 2.5 mm and a volume < 350 mm3 so called small/thin packages. Moisture sensitivity precautions, as indicated on packing, must be respected at all times. 12.3.2 Wave soldering Conventional single wave soldering is not recommended for surface mount devices (SMDs) or printed-circuit boards with a high component density, as solder bridging and non-wetting can present major problems. To overcome these problems the double-wave soldering method was specifically developed. If wave soldering is used the following conditions must be observed for optimal results: • Use a double-wave soldering method comprising a turbulent wave with high upward pressure followed by a smooth laminar wave. • For packages with leads on two sides and a pitch (e): – larger than or equal to 1.27 mm, the footprint longitudinal axis is preferred to be parallel to the transport direction of the printed-circuit board; – smaller than 1.27 mm, the footprint longitudinal axis must be parallel to the transport direction of the printed-circuit board. The footprint must incorporate solder thieves at the downstream end. • For packages with leads on four sides, the footprint must be placed at a 45° angle to the transport direction of the printed-circuit board. The footprint must incorporate solder thieves downstream and at the side corners. During placement and before soldering, the package must be fixed with a droplet of adhesive. The adhesive can be applied by screen printing, pin transfer or syringe dispensing. The package can be soldered after the adhesive is cured. Typical dwell time of the leads in the wave ranges from 3 to 4 seconds at 250 °C or 265 °C, depending on solder material applied, SnPb or Pb-free respectively. A mildly-activated flux will eliminate the need for removal of corrosive residues in most applications. 12.3.3 Manual soldering Fix the component by first soldering two diagonally-opposite end leads. Use a low voltage (24 V or less) soldering iron applied to the flat part of the lead. Contact time must be limited to 10 seconds at up to 300 °C. When using a dedicated tool, all other leads can be soldered in one operation within 2 to 5 seconds between 270 and 320 °C. © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 39 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 12.4 Package related soldering information Table 25: Suitability of IC packages for wave, reflow and dipping soldering methods Mounting Package[1] Soldering method Wave Reflow[2] Dipping − suitable Through-hole mount DBS, DIP, HDIP, RDBS, SDIP, SIL suitable[3] Through-holesurface mount PMFP[4] not suitable not suitable − Surface mount BGA, LBGA, LFBGA, SQFP, SSOP-T[5], TFBGA, VFBGA not suitable suitable − DHVQFN, HBCC, HBGA, HLQFP, HSQFP, HSOP, HTQFP, HTSSOP, HVQFN, HVSON, SMS not suitable[6] suitable − PLCC[7], SO, SOJ suitable suitable − suitable − suitable − [1] [2] [3] [4] [5] [6] [7] [8] [9] recommended[7][8] LQFP, QFP, TQFP not SSOP, TSSOP, VSO, VSSOP not recommended[9] For more detailed information on the BGA packages refer to the (LF)BGA Application Note (AN01026); order a copy from your Philips Semiconductors sales office. All surface mount (SMD) packages are moisture sensitive. Depending upon the moisture content, the maximum temperature (with respect to time) and body size of the package, there is a risk that internal or external package cracks may occur due to vaporization of the moisture in them (the so called popcorn effect). For details, refer to the Drypack information in the Data Handbook IC26; Integrated Circuit Packages; Section: Packing Methods. For SDIP packages, the longitudinal axis must be parallel to the transport direction of the printed-circuit board. Hot bar soldering or manual soldering is suitable for PMFP packages. These transparent plastic packages are extremely sensitive to reflow soldering conditions and must on no account be processed through more than one soldering cycle or subjected to infrared reflow soldering with peak temperature exceeding 217 °C ± 10 °C measured in the atmosphere of the reflow oven. The package body peak temperature must be kept as low as possible. These packages are not suitable for wave soldering. On versions with the heatsink on the bottom side, the solder cannot penetrate between the printed-circuit board and the heatsink. On versions with the heatsink on the top side, the solder might be deposited on the heatsink surface. If wave soldering is considered, then the package must be placed at a 45° angle to the solder wave direction. The package footprint must incorporate solder thieves downstream and at the side corners. Wave soldering is suitable for LQFP, QFP and TQFP packages with a pitch (e) larger than 0.8 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm. Wave soldering is suitable for SSOP and TSSOP packages with a pitch (e) equal to or larger than 0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm. 13. Revision history Table 26: Revision history Rev Date 01 20040329 CPCN Description - Product data (9397 750 11982) © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Product data Rev. 01 — 29 March 2004 40 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs 14. Data sheet status Level Data sheet status[1] Product status[2][3] Definition I Objective data Development This data sheet contains data from the objective specification for product development. Philips Semiconductors reserves the right to change the specification in any manner without notice. II Preliminary data Qualification This data sheet contains data from the preliminary specification. Supplementary data will be published at a later date. Philips Semiconductors reserves the right to change the specification without notice, in order to improve the design and supply the best possible product. III Product data Production This data sheet contains data from the product specification. Philips Semiconductors reserves the right to make changes at any time in order to improve the design, manufacturing and supply. Relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). [1] Please consult the most recently issued data sheet before initiating or completing a design. [2] The product status of the device(s) described in this data sheet may have changed since this data sheet was published. The latest information is available on the Internet at URL http://www.semiconductors.philips.com. [3] For data sheets describing multiple type numbers, the highest-level product status determines the data sheet status. 15. Definitions 16. Disclaimers Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Life support — These products are not designed for use in life support appliances, devices, or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 60134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Right to make changes — Philips Semiconductors reserves the right to make changes in the products - including circuits, standard cells, and/or software - described or contained herein in order to improve design and/or performance. When the product is in full production (status ‘Production’), relevant changes will be communicated via a Customer Product/Process Change Notification (CPCN). Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no licence or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Contact information For additional information, please visit http://www.semiconductors.philips.com. For sales office addresses, send e-mail to: [email protected]. Product data Fax: +31 40 27 24825 © Koninklijke Philips Electronics N.V. 2004. All rights reserved. 9397 750 11982 Rev. 01 — 29 March 2004 41 of 42 SC16C2550B Philips Semiconductors 5 V, 3.3 V and 2.5 V dual UART, 5 Mbit/s (max.), with 16-byte FIFOs Contents 1 2 3 4 5 5.1 5.2 6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 7 7.1 7.2 7.2.1 7.2.2 7.3 7.3.1 7.3.2 7.4 7.5 7.6 7.7 7.8 7.9 7.10 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 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 Loop-back mode . . . . . . . . . . . . . . . . . . . . . . . 13 Register descriptions . . . . . . . . . . . . . . . . . . . 15 Transmit (THR) and Receive (RHR) Holding Registers . . . . . . . . . . . . . . . . . . . . . 15 Interrupt Enable Register (IER) . . . . . . . . . . . 16 IER versus Transmit/Receive FIFO interrupt mode operation . . . . . . . . . . . . . . . . . . . . . . . 17 IER versus Receive/Transmit FIFO polled mode operation . . . . . . . . . . . . . . . . . . . . . . . 17 FIFO Control Register (FCR) . . . . . . . . . . . . . 17 DMA mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FIFO mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Interrupt Status Register (ISR) . . . . . . . . . . . . 19 Line Control Register (LCR) . . . . . . . . . . . . . . 20 Modem Control Register (MCR) . . . . . . . . . . . 22 Line Status Register (LSR) . . . . . . . . . . . . . . . 23 Modem Status Register (MSR). . . . . . . . . . . . 24 Scratchpad Register (SPR) . . . . . . . . . . . . . . 25 SC16C2550B external reset condition . . . . . . 25 © Koninklijke Philips Electronics N.V. 2004. Printed in the U.S.A. All rights are reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license under patent- or other industrial or intellectual property rights. Date of release: 29 March 2004 Document order number: 9397 750 11982 8 9 10 10.1 11 12 12.1 12.2 12.2.1 12.2.2 12.3 12.3.1 12.3.2 12.3.3 12.4 13 14 15 16 Limiting values . . . . . . . . . . . . . . . . . . . . . . . . Static characteristics . . . . . . . . . . . . . . . . . . . Dynamic characteristics . . . . . . . . . . . . . . . . . Timing diagrams. . . . . . . . . . . . . . . . . . . . . . . Package outline . . . . . . . . . . . . . . . . . . . . . . . . Soldering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . Through-hole mount packages . . . . . . . . . . . Soldering by dipping or by solder wave . . . . . Manual soldering . . . . . . . . . . . . . . . . . . . . . . Surface mount packages . . . . . . . . . . . . . . . . Reflow soldering. . . . . . . . . . . . . . . . . . . . . . . Wave soldering. . . . . . . . . . . . . . . . . . . . . . . . Manual soldering . . . . . . . . . . . . . . . . . . . . . . Package related soldering information . . . . . . Revision history . . . . . . . . . . . . . . . . . . . . . . . Data sheet status. . . . . . . . . . . . . . . . . . . . . . . Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 26 27 28 35 38 38 38 38 38 38 38 39 39 40 40 41 41 41