TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 D D D D D D D D D D Programmable Auto-RTS and Auto-CTS In Auto-CTS Mode, CTS Controls Transmitter In Auto-RTS Mode, RCV FIFO Contents and Threshold Control RTS Serial and Modem Control Outputs Drive a RJ11 Cable Directly When Equipment Is on the Same Power Drop Capable of Running With All Existing TL16C450 Software After Reset, All Registers Are Identical to the TL16C450 Register Set Up to 16-MHz Clock Rate for up to 1-Mbaud Operation In the TL16C450 Mode, Hold and Shift Registers Eliminate the Need for Precise Synchronization Between the CPU and Serial Data Programmable Baud Rate Generator Allows Division of Any Input Reference Clock by 1 to (216 – 1) and Generates an Internal 16 × Clock Standard Asynchronous Communication Bits (Start, Stop, and Parity) Added to or Deleted From the Serial Data Stream D D D D D D D D D D D 5-V and 3.3-V Operation Independent Receiver Clock Input Transmit, Receive, Line Status, and Data Set Interrupts Independently Controlled Fully Programmable Serial Interface Characteristics: – 5-, 6-, 7-, or 8-Bit Characters – Even-, Odd-, or No-Parity Bit Generation and Detection – 1-, 1 1/2-, or 2-Stop Bit Generation – Baud Generation (dc to 1 Mbit/s) False-Start Bit Detection Complete Status Reporting Capabilities 3-State Output TTL Drive Capabilities for Bidirectional Data Bus and Control Bus Line Break Generation and Detection Internal Diagnostic Capabilities: – Loopback Controls for Communications Link Fault Isolation – Break, Parity, Overrun, and Framing Error Simulation Fully Prioritized Interrupt System Controls Modem Control Functions (CTS, RTS, DSR, DTR, RI, and DCD) description The TL16C550C and the TL16C550CI are functional upgrades of the TL16C550B asynchronous communications element (ACE), which in turn is a functional upgrade of the TL16C450. Functionally equivalent to the TL16C450 on power up (character or TL16C450 mode), the TL16C550C and the TL16C550CI, like the TL16C550B, can be placed in an alternate FIFO mode. This relieves the CPU of excessive software overhead by buffering received and transmitted characters. The receiver and transmitter FIFOs store up to 16 bytes including three additional bits of error status per byte for the receiver FIFO. In the FIFO mode, there is a selectable autoflow control feature that can significantly reduce software overload and increase system efficiency by automatically controlling serial data flow using RTS output and CTS input signals. The TL16C550C and TL16C550CI perform serial-to-parallel conversions on data received from a peripheral device or modem and parallel-to-serial conversion on data received from its CPU. The CPU can read the ACE status at any time. The ACE includes complete modem control capability and a processor interrupt system that can be tailored to minimize software management of the communications link. Both the TL16C550C and the TL16C550CI ACE include a programmable baud rate generator capable of dividing a reference clock by divisors from 1 to 65535 and producing a 16 × reference clock for the internal transmitter logic. Provisions are included to use this 16 × clock for the receiver logic. The ACE accommodates a 1-Mbaud serial rate (16-MHz input clock) so that a bit time is 1 µs and a typical character time is 10 µs (start bit, 8 data bits, stop bit). Two of the TL16C450 terminal functions on the TL16C550C and the TL16C550CI have been changed to TXRDY and RXRDY, which provide signaling to a DMA controller. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright 2001, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 1 40 2 39 3 38 4 37 5 36 6 35 7 34 8 33 9 32 10 31 11 30 12 29 13 28 14 27 15 26 16 25 17 24 18 23 19 22 20 21 VCC RI DCD DSR CTS MR OUT1 DTR RTS OUT2 INTRPT RXRDY A0 A1 A2 ADS TXRDY DDIS RD2 RD1 6 5 4 D5 D6 D7 RCLK SIN NC SOUT CS0 CS1 CS2 BAUDOUT 7 3 2 1 44 43 42 41 40 39 8 38 9 37 10 36 11 35 12 34 13 33 14 32 15 31 16 30 17 29 18 19 20 21 22 23 24 25 26 27 28 XIN XOUT WR1 WR2 VSS NC RD1 RD2 DDIS TXRDY ADS D0 D1 D2 D3 D4 D5 D6 D7 RCLK SIN SOUT CS0 CS1 CS2 BAUDOUT XIN XOUT WR1 WR2 VSS FN PACKAGE (TOP VIEW) D4 D3 D2 D1 D0 NC VCC RI DCD DSR CTS N PACKAGE (TOP VIEW) NC D4 D3 D2 D1 D0 VCC RI DCD DSR CTS NC PT/PFB PACKAGE (TOP VIEW) 48 47 46 45 44 43 42 41 40 39 38 37 NC D5 D6 D7 RCLK NC SIN SOUT CS0 CS1 CS2 BAUDOUT 1 36 2 35 3 34 4 33 5 32 6 31 7 30 8 29 9 28 10 27 11 26 12 25 NC XIN XOUT WR1 WR2 VSS RD1 RD2 NC DDIS TXRDY ADS 13 14 15 16 17 18 19 20 21 22 23 24 NC – No internal connection 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 NC MR OUT1 DTR RTS OUT2 INTRPT RXRDY A0 A1 A2 NC MR OUT1 DTR RTS OUT2 NC INTRPT RXRDY A0 A1 A2 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 detailed description autoflow control (see Figure 1) Autoflow control is comprised of auto-CTS and auto-RTS. With auto-CTS, the CTS input must be active before the transmitter FIFO can emit data. With auto-RTS, RTS becomes active when the receiver needs more data and notifies the sending serial device. When RTS is connected to CTS, data transmission does not occur unless the receiver FIFO has space for the data; thus, overrun errors are eliminated using ACE1 and ACE2 from a TLC16C550C with the autoflow control enabled. If not, overrun errors occur when the transmit data rate exceeds the receiver FIFO read latency. ACE1 RCV FIFO ACE2 Serial to Parallel Flow Control SIN RTS SOUT CTS Parallel to Serial XMT FIFO Flow Control D7 – D0 D7 – D0 XMT FIFO Parallel to Serial Flow Control SOUT CTS SIN RTS Serial to Parallel RCV FIFO Flow Control Figure 1. Autoflow Control (Auto-RTS and Auto-CTS) Example auto-RTS (see Figure 1) Auto-RTS data flow control originates in the receiver timing and control block (see functional block diagram) and is linked to the programmed receiver FIFO trigger level. When the receiver FIFO level reaches a trigger level of 1, 4, or 8 (see Figure 3), RTS is deasserted. With trigger levels of 1, 4, and 8, the sending ACE may send an additional byte after the trigger level is reached (assuming the sending ACE has another byte to send) because it may not recognize the deassertion of RTS until after it has begun sending the additional byte. RTS is automatically reasserted once the RCV FIFO is emptied by reading the receiver buffer register. When the trigger level is 14 (see Figure 4), RTS is deasserted after the first data bit of the 16th character is present on the SIN line. RTS is reasserted when the RCV FIFO has at least one available byte space. auto-CTS (see Figure 1) The transmitter circuitry checks CTS before sending the next data byte. When CTS is active, it sends the next byte. To stop the transmitter from sending the following byte, CTS must be released before the middle of the last stop bit that is currently being sent (see Figure 2). The auto-CTS function reduces interrupts to the host system. When flow control is enabled, CTS level changes do not trigger host interrupts because the device automatically controls its own transmitter. Without auto-CTS, the transmitter sends any data present in the transmit FIFO and a receiver overrun error may result. enabling autoflow control and auto-CTS Autoflow control is enabled by setting modem control register bits 5 (autoflow enable or AFE) and 1 (RTS) to a 1. Autoflow incorporates both auto-RTS and auto-CTS. When only auto-CTS is desired, bit 1 in the modem control register should be cleared (this assumes that a control signal is driving CTS). POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 auto-CTS and auto-RTS functional timing Start SOUT Bits 0 – 7 Start Stop Bits 0 – 7 Stop Start Bits 0 – 7 Stop CTS NOTES: A. When CTS is low, the transmitter keeps sending serial data out. B. If CTS goes high before the middle of the last stop bit of the current byte, the transmitter finishes sending the current byte but it does not send the next byte. C. When CTS goes from high to low, the transmitter begins sending data again. Figure 2. CTS Functional Timing Waveforms The receiver FIFO trigger level can be set to 1, 4, 8, or 14 bytes. These are described in Figures 3 and 4. SIN Start Byte N Stop Start Byte N+1 Start Stop Byte Stop RTS RD (RD RBR) 1 2 N N+1 NOTES: A. N = RCV FIFO trigger level (1, 4, or 8 bytes) B. The two blocks in dashed lines cover the case where an additional byte is sent as described in the preceding auto-RTS section. Figure 3. RTS Functional Timing Waveforms, RCV FIFO Trigger Level = 1,4, or 8 Bytes SIN RTS Byte 14 Byte 15 Start Byte 16 Stop Start Byte 18 Stop RTS Released After the First Data Bit of Byte 16 RD (RD RBR) NOTES: A. RTS is deasserted when the receiver receives the first data bit of the sixteenth byte. The receive FIFO is full after finishing the sixteenth byte. B. RTS is asserted again when there is at least one byte of space available and no incoming byte is in processing or there is more than one byte of space available. C. When the receive FIFO is full, the first receive buffer register read reasserts RTS. Figure 4. RTS Functional Timing Waveforms, RCV FIFO Trigger Level = 14 Bytes 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 functional block diagram Internal Data Bus 8 –1 D(7 – 0) Data Bus Buffer 8 S e l e c t Receiver FIFO 8 Receiver Shift Register Receiver Buffer Register A0 A2 CS0 CS1 CS2 ADS MR RD1 RD2 WR1 WR2 DDIS TXRDY XIN 9 Receiver Timing and Control Line Control Register A1 10 32 SIN RCLK RTS 28 27 26 Divisor Latch (LS) 12 Divisor Latch (MS) Baud Generator 15 13 14 25 35 21 22 Transmitter Timing and Control Line Status Register Select and Control Logic Transmitter FIFO Transmitter Holding Register 18 19 8 S e l e c t 8 Transmitter Shift Register BAUDOUT Autoflow Control (AFE) 11 SOUT 23 Modem Control Register 24 16 8 36 33 XOUT 17 29 RXRDY Modem Status Register 8 Modem Control Logic 37 38 39 34 VCC 40 20 VSS CTS DTR DSR DCD RI OUT1 31 Power Supply Interrupt Enable Register Interrupt Identification Register 8 Interrupt Control Logic OUT2 30 INTRPT 8 FIFO Control Register NOTE A: Terminal numbers shown are for the N package. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 Terminal Functions TERMINAL NO. N NO. FN NO. PT I/O DESCRIPTION A0 A1 A2 28 27 26 31 30 29 28 27 26 I Register select. A0 – A2 are used during read and write operations to select the ACE register to read from or write to. Refer to Table 1 for register addresses and refer to ADS description. ADS 25 28 24 I Address strobe. When ADS is active (low), A0, A1, and A2 and CS0, CS1, and CS2 drive the internal select logic directly; when ADS is high, the register select and chip select signals are held at the logic levels they were in when the low-to-high transition of ADS occurred. BAUDOUT 15 17 12 O Baud out. BAUDOUT is a 16 × clock signal for the transmitter section of the ACE. The clock rate is established by the reference oscillator frequency divided by a divisor specified by the baud generator divisor latches. BAUDOUT may also be used for the receiver section by tying this output to RCLK. CS0 CS1 CS2 12 13 14 14 15 16 9 10 11 I Chip select. When CS0 and CS1 are high and CS2 is low, these three inputs select the ACE. When any of these inputs are inactive, the ACE remains inactive (refer to ADS description). CTS 36 40 38 I Clear to send. CTS is a modem status signal. Its condition can be checked by reading bit 4 (CTS) of the modem status register. Bit 0 (∆ CTS) of the modem status register indicates that CTS has changed states since the last read from the modem status register. If the modem status interrupt is enabled when CTS changes levels and the auto-CTS mode is not enabled, an interrupt is generated. CTS is also used in the auto-CTS mode to control the transmitter. D0 D1 D2 D3 D4 D5 D6 D7 1 2 3 4 5 6 7 8 2 3 4 5 6 7 8 9 43 44 45 46 47 2 3 4 I/O Data bus. Eight data lines with 3-state outputs provide a bidirectional path for data, control, and status information between the ACE and the CPU. DCD 38 42 40 I Data carrier detect. DCD is a modem status signal. Its condition can be checked by reading bit 7 (DCD) of the modem status register. Bit 3 (∆ DCD) of the modem status register indicates that DCD has changed states since the last read from the modem status register. If the modem status interrupt is enabled when DCD changes levels, an interrupt is generated. DDIS 23 26 22 O Driver disable. DDIS is active (high) when the CPU is not reading data. When active, DDIS can disable an external transceiver. DSR 37 41 39 I Data set ready. DSR is a modem status signal. Its condition can be checked by reading bit 5 (DSR) of the modem status register. Bit 1 (∆ DSR) of the modem status register indicates DSR has changed levels since the last read from the modem status register. If the modem status interrupt is enabled when DSR changes levels, an interrupt is generated. DTR 33 37 33 O Data terminal ready. When active (low), DTR informs a modem or data set that the ACE is ready to establish communication. DTR is placed in the active level by setting the DTR bit of the modem control register. DTR is placed in the inactive level either as a result of a master reset, during loop mode operation, or clearing the DTR bit. INTRPT 30 33 30 O Interrupt. When active (high), INTRPT informs the CPU that the ACE has an interrupt to be serviced. Four conditions that cause an interrupt to be issued are: a receiver error, received data that is available or timed out (FIFO mode only), an empty transmitter holding register, or an enabled modem status interrupt. INTRPT is reset (deactivated) either when the interrupt is serviced or as a result of a master reset. MR 35 39 35 I Master reset. When active (high), MR clears most ACE registers and sets the levels of various output signals (refer to Table 2). NAME 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 Terminal Functions (Continued) TERMINAL NO. N NO. FN NO. PT I/O DESCRIPTION 34 31 38 35 34 31 O Outputs 1 and 2. These are user-designated output terminals that are set to the active (low) level by setting respective modem control register (MCR) bits (OUT1 and OUT2). OUT1 and OUT2 are set to inactive the (high) level as a result of master reset, during loop mode operations, or by clearing bit 2 (OUT1) or bit 3 (OUT2) of the MCR. RCLK 9 10 5 I Receiver clock. RCLK is the 16 × baud rate clock for the receiver section of the ACE. RD1 RD2 21 22 24 25 19 20 I Read inputs. When either RD1 or RD2 is active (low or high respectively) while the ACE is selected, the CPU is allowed to read status information or data from a selected ACE register. Only one of these inputs is required for the transfer of data during a read operation; the other input should be tied to its inactive level (i.e., RD2 tied low or RD1 tied high). RI 39 43 41 I Ring indicator. RI is a modem status signal. Its condition can be checked by reading bit 6 (RI) of the modem status register. Bit 2 (TERI) of the modem status register indicates that RI has transitioned from a low to a high level since the last read from the modem status register. If the modem status interrupt is enabled when this transition occurs, an interrupt is generated. RTS 32 36 32 O Request to send. When active, RTS informs the modem or data set that the ACE is ready to receive data. RTS is set to the active level by setting the RTS modem control register bit and is set to the inactive (high) level either as a result of a master reset or during loop mode operations or by clearing bit 1 (RTS) of the MCR. In the auto-RTS mode, RTS is set to the inactive level by the receiver threshold control logic. RXRDY 29 32 29 O Receiver ready. Receiver direct memory access (DMA) signalling is available with RXRDY. When operating in the FIFO mode, one of two types of DMA signalling can be selected using the FIFO control register bit 3 (FCR3). When operating in the TL16C450 mode, only DMA mode 0 is allowed. Mode 0 supports single-transfer DMA in which a transfer is made between CPU bus cycles. Mode 1 supports multitransfer DMA in which multiple transfers are made continuously until the receiver FIFO has been emptied. In DMA mode 0 (FCR0 = 0 or FCR0 = 1, FCR3 = 0), when there is at least one character in the receiver FIFO or receiver holding register, RXRDY is active (low). When RXRDY has been active but there are no characters in the FIFO or holding register, RXRDY goes inactive (high). In DMA mode 1 (FCR0 = 1, FCR3 = 1), when the trigger level or the time-out has been reached, RXRDY goes active (low); when it has been active but there are no more characters in the FIFO or holding register, it goes inactive (high). SIN 10 11 7 I Serial data input. SIN is serial data input from a connected communications device SOUT 11 13 8 O Serial data output. SOUT is composite serial data output to a connected communication device. SOUT is set to the marking (high) level as a result of master reset. TXRDY 24 27 23 O Transmitter ready. Transmitter DMA signalling is available with TXRDY. When operating in the FIFO mode, one of two types of DMA signalling can be selected using FCR3. When operating in the TL16C450 mode, only DMA mode 0 is allowed. Mode 0 supports single-transfer DMA in which a transfer is made between CPU bus cycles. Mode 1 supports multitransfer DMA in which multiple transfers are made continuously until the transmit FIFO has been filled. VCC VSS 40 44 42 5-V supply voltage 20 22 18 Supply common WR1 WR2 18 19 20 21 16 17 I XIN XOUT 16 17 18 19 14 15 I/O NAME OUT1 OUT2 Write inputs. When either WR1 or WR2 is active (low or high respectively) and while the ACE is selected, the CPU is allowed to write control words or data into a selected ACE register. Only one of these inputs is required to transfer data during a write operation; the other input should be tied to its inactive level (i.e., WR2 tied low or WR1 tied high). External clock. XIN and XOUT connect the ACE to the main timing reference (clock or crystal). POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V Input voltage range at any input, VI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V Output voltage range, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.5 V to 7 V Operating free-air temperature range, TA, TL16C550C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C TL16C550CI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –40°C to 85°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Case temperature for 10 seconds, TC: FN package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: N or PT package . . . . . . . . . . . . . . . 260°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: All voltage values are with respect to VSS. recommended operating conditions low voltage (3.3 V nominal) MIN NOM Supply voltage, VCC 3 3.3 Input voltage, VI 0 High-level input voltage, VIH (see Note 2) MAX 3.6 V VCC V 0.7 VCC V Low-level input voltage, VIL (see Note 2) Output voltage, VO (see Note 3) UNIT 0 High-level output current, IOH (all outputs) Low-level output current, IOL (all outputs) Input capacitance 0.3 VCC V VCC 1.8 V mA 3.2 mA 1 pF °C Operating free-air temperature, TA 0 25 70 Junction temperature range, TJ (see Note 4) 0 25 115 °C 14 MHz Oscillator/clock speed NOTES: 2. Meets TTL levels, VIHmin = 2 V and VILmax = 0.8 V on nonhysteresis inputs 3. Applies for external output buffers 4. These junction temperatures reflect simulated conditions. Absolute maximum junction temperature is 150°C. The customer is responsible for verifying junction temperature. standard voltage (5 V nominal) Supply voltage, VCC MIN NOM MAX UNIT 4.75 5 5.25 V VCC V Input voltage, VI 0 High-level input voltage, VIH 2 V Low-level input voltage, VIL 0.8 Output voltage, VO (see Note 5) 0 V VCC 4 mA Low-level output current, IOL (all outputs) 4 mA Input capacitance 1 pF °C High-level output current, IOH (all outputs) V Operating free-air temperature, TA 0 25 70 Junction temperature range, TJ (see Note 6) 0 25 115 °C 16 MHz Oscillator/clock speed 5. Applies for external output buffers 6. These junction temperatures reflect simulated conditions. Absolute maximum junction temperature is 150°C. The customer is responsible for verifying junction temperature. 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 electrical characteristics over recommended ranges of supply voltage and operating free-air temperature (unless otherwise noted) low voltage (3.3 V nominal) PARAMETER TEST CONDITIONS VOH‡ VOL‡ High-level output voltage Il Input current VCC = 3.6 V,, VI = 0 to 3.6 V, IOZ High-impedance-state g output current VSS = 0, VCC = 3.6 V, VO = 0 to 3.6 V, Chip selected in write mode or chip deselect ICC Supply Su ly current 6V TA = 25°C VCC = 3 3.6 V, 25 C, SIN, SIN DSR, DSR DCD, DCD CTS, CTS and RI at 2 V, V 0 8 V, V MHz All other inputs at 0.8 XTAL1 at 4 MHz, No Baud kbit/s N lload d on outputs, t t B d rate t = 50 kbit/ Ci(CLK) Clock input capacitance Low-level output voltage Co(CLK) Clock output capacitance Ci Input capacitance IOH = – 1 mA IOL = 1.6 mA MIN TYP† MAX 2.4 V 0.5 V 10 µA ± 20 µA µ 8 mA 15 20 pF 20 30 pF 6 10 pF 10 20 pF TYP† MAX VSS = 0,, All other terminals floating VCC = 0, VSS = 0, f = 1 MHz, TA = 25°C 25°C, MHz All other terminals grounded Co Output capacitance † All typical values are at VCC = 3.3 V and TA = 25°C. ‡ These parameters apply for all outputs except XOUT. UNIT standard voltage (5 V nominal) PARAMETER VOH‡ VOL‡ High-level output voltage Low-level output voltage TEST CONDITIONS IOH = – 1 mA IOL = 1.6 mA 2.4 Il Input current VCC = 5.25 V,, VI = 0 to 5.25 V, IOZ High-impedance-state output current g VCC = 5.25 V, VSS = 0, VO = 0 to 5.25 V, Chip selected in write mode or chip deselect ICC Supply Su ly current VCC = 5 5.25 25 V V, TA = 25°C 25 C, SIN DSR, SIN, DSR DCD, DCD CTS, CTS and RI at 2 V, V All other inputs at 0.8 0 8 V, V XTAL1 at 4 MHz, MHz N lload No d on outputs, t t B Baud d rate t = 50 kbit/ kbit/s Ci(CLK) Clock input capacitance Co(CLK) Clock output capacitance Ci Input capacitance Co Output capacitance † All typical values are at VCC = 5 V and TA = 25°C. ‡ These parameters apply for all outputs except XOUT. • DALLAS, TEXAS 75265 UNIT V 0.4 V 10 µA ± 20 µA µ 10 mA 15 20 pF 20 30 pF 6 10 pF 10 20 pF VSS = 0,, All other terminals floating VCC = 0, VSS = 0, f = 1 MHz, MHz TA = 25°C 25°C, All other terminals grounded POST OFFICE BOX 655303 MIN 9 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 system timing requirements over recommended ranges of supply voltage and operating free-air temperature ALT. SYMBOL FIGURE TEST CONDITIONS MIN MAX UNIT tcR tcW Cycle time, read (tw7 + td8 + td9) RC 87 ns Cycle time, write (tw6 + td5 + td6) WC 87 ns tw1 tw2 Pulse duration, clock high tXH tXL 25 ns tw5 tw6 Pulse duration, ADS low tw7 tw8 Pulse duration, RD tsu1 tsu2 Setup time, address valid before ADS↑ Setup time, CS valid before ADS↑ tAS tCS tsu3 tsu4 Setup time, data valid before WR1↑ or WR2↓ tDS th1 th2 Hold time, address low after ADS↑ th3 th4 Hold time, CS valid after WR1↑ or WR2↓ th5 th6 Hold time, data valid after WR1↑ or WR2↓ th7 td4† Hold time, address valid after RD1↑ or RD2↓ td5† td6† Delay time, address valid before WR1↓ or WR2↑ td7† td8† Delay time, CS valid to RD1↓ or RD2↑ td9 td10 Delay time, read cycle, RD1↑ or RD2↓ to ADS↓ Pulse duration, clock low Pulse duration, WR Pulse duration, MR Hold time, address valid after WR1↑ or WR2↓ Hold time, chip select valid after RD1↑ or RD2↓ Delay time, CS valid before WR1↓ or WR2↑ Delay time, write cycle, WR1↑ or WR2↓ to ADS↓ Delay time, address valid to RD1↓ or RD2↑ Delay time, RD1↓ or RD2↑ to data valid td11 Delay time, RD1↑ or RD2↓ to floating data † Only applies when ADS is low f = 16 MHz Max, VCC = 5 V tADS tWR 6, 7 9 ns 6 40 ns tRD tMR 7 40 ns 1 µs 6 7 6, 8 ns 6 15 ns 17 10 ns tAH tCH 6 7 6, 0 ns tWCS tWA 6 10 ns tDH 6 5 ns tRCS tRA 7 10 ns 7 20 ns 6 7 ns tWC tCSR tAR 6 40 ns 7 7 ns tRC 7 40 ns tRVD tHZ 7 CL = 75 pF 45 ns 7 CL = 75 pF 20 ns Setup time, CTS↑ before midpoint of stop bit Hold time, CS valid after ADS↑ 5 tCSW tAW system switching characteristics over recommended ranges of supply voltage and operating free-air temperature (see Note 7) PARAMETER ALT. SYMBOL FIGURE tdis(R) Disable time, RD1↓↑ or RD2↑↓ to DDIS↑↓ tRDD 7 NOTE 7: Charge and discharge times are determined by VOL, VOH, and external loading. TEST CONDITIONS CL = 75 pF MIN MAX 20 UNIT ns baud generator switching characteristics over recommended ranges of supply voltage and operating free-air temperature, CL = 75 pF PARAMETER ALT. SYMBOL FIGURE TEST CONDITIONS MIN 5 f = 16 MHz, CLK ÷ 2, VCC = 5 V 50 5 45 ns 5 45 ns tw3 tw4 Pulse duration, BAUDOUT low td1 td2 Delay time, XIN↑ to BAUDOUT↑ tLW tHW tBLD Delay time, XIN↑↓ to BAUDOUT↓ tBHD 10 Pulse duration, BAUDOUT high POST OFFICE BOX 655303 5 • DALLAS, TEXAS 75265 MAX UNIT ns TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 receiver switching characteristics over recommended ranges of supply voltage and operating free-air temperature (see Note 8) ALT. SYMBOL FIGURE td12 Delay time, RCLK to sample PARAMETER tSCD 8 TEST CONDITIONS MIN 10 ns td13 Delay time, stop to set INTRPT or read RBR to LSI interrupt or stop to RXRDY↓ tSINT 8, 9, 10, 11, 12 1 RCLK cycle td14 Delay time, read RBR/LSR to reset INTRPT tRINT 8, 9, 10, 11, 12 70 ns CL = 75 pF MAX UNIT NOTE 8: In the FIFO mode, the read cycle (RC) = 425 ns (min) between reads of the receive FIFO and the status registers (interrupt identification register or line status register). transmitter switching characteristics over recommended ranges of supply voltage and operating free-air temperature PARAMETER ALT. SYMBOL FIGURE td15 Delay time, initial write to transmit start tIRS td16 Delay time, start to INTRPT td17 Delay time, WR (WR THR) to reset INTRPT TEST CONDITIONS MIN MAX 13 8 24 baudout cycles tSTI 13 8 10 baudout cycles tHR 13 CL = 75 pF UNIT 50 ns 34 baudout cycles ns td18 Delay time, initial write to INTRPT (THRE†) tSI 13 td19 Delay time, read IIR† to reset INTRPT (THRE†) tIR 13 CL = 75 pF 35 td20 Delay time, write to TXRDY inactive tWXI 14,15 CL = 75 pF 35 ns 9 baudout cycles td21 tSXA Delay time, start to TXRDY active 16 14,15 CL = 75 pF † THRE = transmitter holding register empty; IIR = interrupt identification register. modem control switching characteristics over recommended ranges of supply voltage and operating free-air temperature, CL = 75 pF PARAMETER ALT. SYMBOL FIGURE MIN MAX UNIT td22 td23 Delay time, WR MCR to output tMDO tSIM 16 50 ns Delay time, modem interrupt to set INTRPT 16 35 ns td24 Delay time, RD MSR to reset INTRPT tRIM 16 40 ns td25 Delay time, CTS low to SOUT↓ 17 24 baudout cycles td26 Delay time, RCV threshold byte to RTS↑ 18 2 baudout cycles td27 Delay time, read of last byte in receive FIFO to RTS↓ 18 2 baudout cycles td28 Delay time, first data bit of 16th character to RTS↑ 19 2 baudout cycles td29 Delay time, RBRRD low to RTS↓ 19 2 baudout cycles POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION N tw1 tw2 XIN td2 td1 BAUDOUT (1/1) td1 td2 BAUDOUT (1/2) tw3 tw4 BAUDOUT (1/3) BAUDOUT (1/N) (N > 3) 2 XIN Cycles (N – 2) XIN Cycles Figure 5. Baud Generator Timing Waveforms 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION tw5 50% ADS 50% 50% tsu1 th1 A0 – A2 50% 50% Valid † Valid 50% tsu2 th2 CS0, CS1, CS2 50% th3 tw6 td4 td5 WR1, WR2 Valid † Valid 50% th4† td6 50% Active 50% tsu3 th5 Valid Data D7 – D0 † Applicable only when ADS is low Figure 6. Write Cycle Timing Waveforms POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION tw5 50% ADS 50% 50% tsu1 th1 A0 – A2 Valid 50% 50% Valid† 50% tsu2 th2 CS0, CS1, CS2 50% Valid td7† td8† 50% RD1, RD2 50% Valid† th6 tw7 50% th7† td9 Active 50% tdis(R) DDIS tdis(R) 50% 50% td10 D7 – D0 td11 Valid Data † Applicable only when ADS is low Figure 7. Read Cycle Timing Waveforms 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION RCLK td12 8 CLKs Sample Clock TL16C450 Mode: SIN Start Data Bits 5– 8 Parity Stop Sample Clock INTRPT (data ready) 50% td13 INTRPT (RCV error) 50% td14 50% 50% RD1, RD2 (read RBR) 50% RD1, RD2 (read LSR) 50% Active Active td14 Figure 8. Receiver Timing Waveforms POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION SIN Data Bits 5 – 8 Stop Sample Clock Trigger Level INTRPT (FCR6, 7 = 0, 0) 50% (FIFO at or above trigger level) 50% (FIFO below trigger level) td13 (see Note A) td14 INTRPT Line Status Interrupt (LSI) 50% 50% td14 RD1 (RD LSR) Active 50% Active RD1 (RD RBR) 50% NOTE A: For a time-out interrupt, td13 = 9 RCLKs. Figure 9. Receive FIFO First Byte (Sets DR Bit) Waveforms SIN Stop Sample Clock Time-Out or Trigger Level Interrupt 50% 50% (FIFO below trigger level) td13 (see Note A) td14 50% Line Status Interrupt (LSI) 50% Top Byte of FIFO td13 td14 RD1, RD2 (RD LSR) RD1, RD2 (RD RBR) (FIFO at or above trigger level) 50% Active 50% 50% Active Previous Byte Read From FIFO NOTE A: For a time-out interrupt, td13 = 9 RCLKs. Figure 10. Receive FIFO Bytes Other Than the First Byte (DR Internal Bit Already Set) Waveforms 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION RD (RD RBR) 50% Active See Note A SIN (first byte) Stop Sample Clock td13 (see Note B) td14 50% 50% RXRDY NOTE A: This is the reading of the last byte in the FIFO. Figure 11. Receiver Ready (RXRDY) Waveforms, FCR0 = 0 or FCR0 = 1 and FCR3 = 0 (Mode 0) RD (RD RBR) 50% Active See Note A SIN (first byte that reaches the trigger level) Sample Clock td13 (see Note B) RXRDY td14 50% 50% NOTES: A. This is the reading of the last byte in the FIFO. B. For a time-out interrupt, td13 = 9 RCLKs. Figure 12. Receiver Ready (RXRDY) Waveforms, FCR0 = 1 and FCR3 = 1 (Mode 1) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION Start 50% SOUT Data Bits Parity td15 INTRPT (THRE) 50% Start 50% Stop td16 50% 50% 50% 50% td18 td17 td17 WR 50% (WR THR) 50% 50% td19 RD IIR 50% Figure 13. Transmitter Timing Waveforms WR (WR THR) SOUT Byte #1 50% Data Parity Stop Start 50% td21 td20 TXRDY 50% 50% Figure 14. Transmitter Ready (TXRDY) Waveforms, FCR0 = 0 or FCR0 = 1 and FCR3 = 0 (Mode 0) Byte #16 WR (WR THR) SOUT 50% Data Parity Stop td21 td20 TXRDY Start 50% 50% FIFO Full 50% Figure 15. Transmitter Ready (TXRDY) Waveforms, FCR0 = 1 and FCR3 = 1 (Mode 1) 18 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION WR (WR MCR) 50% 50% td22 td22 RTS, DTR, OUT1, OUT2 50% 50% 50% CTS, DSR, DCD td23 INTRPT (modem) 50% 50% 50% td24 td23 RD2 (RD MSR) 50% RI 50% Figure 16. Modem Control Timing Waveforms tsu4 CTS 50% 50% td25 SOUT 50% Midpoint of Stop Bit Figure 17. CTS and SOUT Autoflow Control Timing (Start and Stop) Waveforms Midpoint of Stop Bit SIN td26 RTS td27 50% 50% 50% RBRRD Figure 18. Auto-RTS Timing for RCV Threshold of 1, 4, or 8 Waveforms POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PARAMETER MEASUREMENT INFORMATION Midpoint of Data Bit 0 15th Character SIN 16th Character td29 td28 50% 50% RTS 50% RBRRD Figure 19. Auto-RTS Timing for RCV Threshold of 14 Waveforms APPLICATION INFORMATION SOUT D7 – D0 D7 – D0 MEMR or I/OR MEMW or I/ON INTR C P U B u s RESET A0 A1 A2 SIN RD1 RTS WR1 DTR INTRPT DSR MR DCD A0 A1 EIA 232-D Drivers and Receivers CTS TL16C550C (ACE) RI A2 ADS XIN WR2 L 3.072 MHz RD2 CS H CS2 XOUT CS1 BAUDOUT CS0 RCLK Figure 20. Basic TL16C550C Configuration 20 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 APPLICATION INFORMATION Receiver Disable WR WR1 TL16C550C (ACE) Microcomputer System Data Bus Data Bus 8-Bit Bus Transceiver D7 – D0 DDIS Driver Disable Figure 21. Typical Interface for a High Capacity Data Bus POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 21 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 APPLICATION INFORMATION TL16C550C XIN A16 – A23 A16 – A23 XOUT 16 Alternate Crystal Control 17 15 12 BAUDOUT CS0 Address Decoder CPU 13 14 RCLK CS1 CS2 DTR 25 ADS RTS 32 1 OUT2 31 A0 – A2 AD0 – AD7 Buffer D0 – D7 39 RI 38 PHI1 20 OUT1 MR AD0 – AD15 33 34 ADS 35 RSI/ABT 9 DCD PHI2 8 37 6 DSR CTS PHI1 ADS PHI2 RSTO RD 21 TCU 18 WR RD1 36 11 SOUT 2 WR1 10 SIN INTRPT TXRDY 22 19 RD2 DDIS WR2 GND (VSS) RXRDY 20 23 29 40 5V (VCC) NOTE A: Terminal numbers shown are for the N package. Figure 22. Typical TL16C550C Connection to a CPU POST OFFICE BOX 655303 3 30 24 AD0 – AD15 22 5 • DALLAS, TEXAS 75265 7 1 EIA-232-D Connector TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION Table 1. Register Selection DLAB† A2 A1 A0 0 L L L Receiver buffer (read), transmitter holding register (write) 0 L L H Interrupt enable register X L H L Interrupt identification register (read only) X L H L FIFO control register (write) X L H H Line control register X H L L Modem control register X H L H Line status register X H H L Modem status register X H H H Scratch register 1 L L L Divisor latch (LSB) REGISTER 1 L L H Divisor latch (MSB) † The divisor latch access bit (DLAB) is the most significant bit of the line control register. The DLAB signal is controlled by writing to this bit location (see Table 4). Table 2. ACE Reset Functions REGISTER/SIGNAL RESET CONTROL RESET STATE Interrupt enable register Master reset All bits cleared (0 – 3 forced and 4 – 7 permanent) Interrupt identification register Master reset Bit 0 is set, bits 1, 2, 3, 6, and 7 are cleared, and bits 4 – 5 are permanently cleared FIFO control register Master reset All bits cleared Line control register Master reset All bits cleared Modem control register Master reset All bits cleared (6 – 7 permanent) Line status register Master reset Bits 5 and 6 are set; all other bits are cleared Modem status register Master reset Bits 0 – 3 are cleared; bits 4 – 7 are input signals SOUT Master reset High INTRPT (receiver error flag) Read LSR/MR Low INTRPT (received data available) Read RBR/MR Low Read IR/write THR/MR Low Read MSR/MR Low OUT2 Master reset High RTS Master reset High DTR Master reset High OUT1 Master reset High Scratch register Master reset No effect Divisor latch (LSB and MSB) registers Master reset No effect Receiver buffer register Master reset No effect Transmitter holding register Master reset No effect INTRPT (transmitter holding register empty) INTRPT (modem status changes) RCVR FIFO MR/FCR1 – FCR0/∆FCR0 All bits cleared XMIT FIFO MR/FCR2 – FCR0/∆FCR0 All bits cleared POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 23 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION accessible registers The system programmer, using the CPU, has access to and control over any of the ACE registers that are summarized in Table 2. These registers control ACE operations, receive data, and transmit data. Descriptions of these registers follow Table 3. Table 3. Summary of Accessible Registers REGISTER ADDRESS BIT NO. 0 1 2 3 0 DLAB = 0 0 DLAB = 0 Receiver Buffer Register (Read Only) Transmitter Holding Register (Write Only) RBR Data Bit 0† Data Bit 1 Data Bit 2 Data Bit 3 1 DLAB = 0 2 2 3 4 5 6 7 0 DLAB = 1 1 DLAB = 1 Interrupt Enable Register Interrupt Ident. Register (Read Only) FIFO Control Register (Write Only) Line Control Register Modem Control Register Line Status Register Modem Status Register Scratch Register Divisor Latch (LSB) Latch (MSB) THR IER IIR FCR LCR MCR LSR MSR SCR DLL DLM Data Bit 0 Enable Received Data Available Interrupt (ERBI) 0 if Interrupt Pending FIFO Enable Word Length Select Bit 0 (WLS0) Data Terminal Ready (DTR) Data Ready (DR) Delta Clear to Send Bit 0 Bit 0 Bit 8 Enable Transmitter Holding Register Empty Interrupt (ETBEI) Interrupt ID Bit 1 Receiver FIFO Reset Word Length Select Bit 1 (WLS1) Request to Send (RTS) Overrun Error (OE) Bit 1 Bit 1 Bit 9 Data Bit 2 Enable Receiver Line Status Interrupt (ELSI) Interrupt ID Bit 2 Transmitter FIFO Reset Number of Stop Bits (STB) OUT1 Parity Error (PE) Trailing Edge Ring Indicator (TERI) Bit 2 Bit 2 Bit 10 Data Bit 3 Enable Modem Status Interrupt (EDSSI) Interrupt ID Bit 3 (see Note 9) DMA Mode Select Parity Enable (PEN) OUT2 Framing Error (FE) Delta Data Carrier Detect Bit 3 Bit 3 Bit 11 Loop Break Interrupt (BI) Clear to Send (CTS) Bit 4 Bit 4 Bit 12 Data Bit 1 Delta Data Set Ready (∆DSR) (∆DCD) 4 Data Bit 4 Data Bit 4 0 0 Reserved Even Parity Select (EPS) 5 Data Bit 5 Data Bit 5 0 0 Reserved Stick Parity Autoflow Control Enable (AFE) Transmitter Holding Register (THRE) Data Set Ready (DSR) Bit 5 Bit 5 Bit 13 6 Data Bit 6 Data Bit 6 0 FIFOs Enabled (see Note 9) Receiver Trigger (LSB) Break Control 0 Transmitter Empty (TEMT) Ring Indicator (RI) Bit 6 Bit 6 Bit 14 7 Data Bit 7 Data Bit 7 0 FIFOs Enabled (see Note 9) Receiver Trigger (MSB) Divisor Latch Access Bit (DLAB) 0 Error in RCVR FIFO (see Note 9) Data Carrier Detect (DCD) Bit 7 Bit 7 Bit 15 † Bit 0 is the least significant bit. It is the first bit serially transmitted or received. NOTE 9: These bits are always 0 in the TL16C450 mode. 24 (∆CTS) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION FIFO control register (FCR) The FCR is a write-only register at the same location as the IIR, which is a read-only register. The FCR enables and clears the FIFOs, sets the receiver FIFO trigger level, and selects the type of DMA signalling. D D D D D D Bit 0: This bit, when set, enables the transmitter and receiver FIFOs. Bit 0 must be set when other FCR bits are written to or they are not programmed. Changing this bit clears the FIFOs. Bit 1: This bit, when set, clears all bytes in the receiver FIFO and clears its counter. The shift register is not cleared. The 1 that is written to this bit position is self clearing. Bit 2: This bit, when set, clears all bytes in the transmit FIFO and clears its counter. The shift register is not cleared. The 1 that is written to this bit position is self clearing. Bit 3: When FCR0 is set, setting FCR3 causes RXRDY and TXRDY to change from level 0 to level 1. Bits 4 and 5: These two bits are reserved for future use. Bits 6 and 7: These two bits set the trigger level for the receiver FIFO interrupt (see Table 4). Table 4. Receiver FIFO Trigger Level BIT 7 BIT 6 RECEIVER FIFO TRIGGER LEVEL (BYTES) 0 0 01 0 1 04 1 0 08 1 1 14 FIFO interrupt mode operation When the receiver FIFO and receiver interrupts are enabled (FCR0 = 1, IER0 = 1, IER2 = 1), a receiver interrupt occurs as follows: 1. The received data available interrupt is issued to the microprocessor when the FIFO has reached its programmed trigger level. It is cleared when the FIFO drops below its programmed trigger level. 2. The IIR receive data available indication also occurs when the FIFO trigger level is reached, and like the interrupt, it is cleared when the FIFO drops below the trigger level. 3. The receiver line status interrupt (IIR = 06) has higher priority than the received data available (IIR = 04) interrupt. 4. The data ready bit (LSR0) is set when a character is transferred from the shift register to the receiver FIFO. It is cleared when the FIFO is empty. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 25 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION FIFO interrupt mode operation (continued) When the receiver FIFO and receiver interrupts are enabled: 1. FIFO time-out interrupt occurs if the following conditions exist: a. At least one character is in the FIFO. b. The most recent serial character was received more than four continuous character times ago (if two stop bits are programmed, the second one is included in this time delay). c. The most recent microprocessor read of the FIFO has occurred more than four continuous character times before. This causes a maximum character received command to interrupt an issued delay of 160 ms at a 300 baud rate with a 12-bit character. 2. Character times are calculated by using the RCLK input for a clock signal (makes the delay proportional to the baud rate). 3. When a time-out interrupt has occurred, it is cleared and the timer is cleared when the microprocessor reads one character from the receiver FIFO. 4. When a time-out interrupt has not occurred, the time-out timer is cleared after a new character is received or after the microprocessor reads the receiver FIFO. When the transmitter FIFO and THRE interrupt are enabled (FCR0 = 1, IER1 = 1), transmit interrupts occur as follows: 1. The transmitter holding register empty interrupt [IIR (3 –0) = 2] occurs when the transmit FIFO is empty. It is cleared [IIR (3 –0) = 1] when the THR is written to (1 to 16 characters may be written to the transmit FIFO while servicing this interrupt) or the IIR is read. 2. The transmitter holding register empty interrupt is delayed one character time minus the last stop bit time when there have not been at least two bytes in the transmitter FIFO at the same time since the last time that the FIFO was empty. The first transmitter interrupt after changing FCR0 is immediate if it is enabled. FIFO polled mode operation With FCR0 = 1 (transmitter and receiver FIFOs enabled), clearing IER0, IER1, IER2, IER3, or all four to 0 puts the ACE in the FIFO polled mode of operation. Since the receiver and transmitter are controlled separately, either one or both can be in the polled mode of operation. In this mode, the user program checks receiver and transmitter status using the LSR. As stated previously: D D D D D LSR0 is set as long as there is one byte in the receiver FIFO. LSR1 – LSR 4 specify which error(s) have occurred. Character error status is handled the same way as when in the interrupt mode; the IIR is not affected since IER2 = 0. LSR5 indicates when the THR is empty. LSR6 indicates that both the THR and TSR are empty. LSR7 indicates whether there are any errors in the receiver FIFO. There is no trigger level reached or time-out condition indicated in the FIFO polled mode. However, the receiver and transmitter FIFOs are still fully capable of holding characters. 26 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION interrupt enable register (IER) The IER enables each of the five types of interrupts (refer to Table 5) and enables INTRPT in response to an interrupt generation. The IER can also disable the interrupt system by clearing bits 0 through 3. The contents of this register are summarized in Table 3 and are described in the following bullets. D D D D D Bit 0: When set, this bit enables the received data available interrupt. Bit 1: When set, this bit enables the THRE interrupt. Bit 2: When set, this bit enables the receiver line status interrupt. Bit 3: When set, this bit enables the modem status interrupt. Bits 4 through 7: These bits are not used (always cleared). interrupt identification register (IIR) The ACE has an on-chip interrupt generation and prioritization capability that permits a flexible interface with most popular microprocessors. The ACE provides four prioritized levels of interrupts: D D D D Priority 1 – Receiver line status (highest priority) Priority 2 – Receiver data ready or receiver character time-out Priority 3 – Transmitter holding register empty Priority 4 – Modem status (lowest priority) When an interrupt is generated, the IIR indicates that an interrupt is pending and encodes the type of interrupt in its three least significant bits (bits 0, 1, and 2). The contents of this register are summarized in Table 3 and described in Table 5. Detail on each bit is as follows: D D D D D Bit 0: This bit is used either in a hardwire prioritized or polled interrupt system. When bit 0 is cleared, an interrupt is pending If bit 0 is set, no interrupt is pending. Bits 1 and 2: These two bits identify the highest priority interrupt pending as indicated in Table 3 Bit 3: This bit is always cleared in TL16C450 mode. In FIFO mode, bit 3 is set with bit 2 to indicate that a time-out interrupt is pending. Bits 4 and 5: These two bits are not used (always cleared). Bits 6 and 7: These bits are always cleared in TL16C450 mode. They are set when bit 0 of the FIFO control register is set. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 27 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION interrupt identification register (IIR) (continued) Table 5. Interrupt Control Functions INTERRUPT IDENTIFICATION REGISTER PRIORITY LEVEL INTERRUPT TYPE None INTERRUPT SOURCE INTERRUPT RESET METHOD None None BIT 3 BIT 2 BIT 1 BIT 0 0 0 0 1 None 0 1 1 0 1 Receiver line status Overrun error, parity error, Read the line status register framing error, or break interrupt 0 1 0 0 2 Received data available Receiver data available in the TL16C450 mode or trigger level Read the receiver buffer register reached in the FIFO mode 2 Character time-out indication No characters have been removed from or input to the receiver FIFO during the last four Read the receiver buffer register character times, and there is at least one character in it during this time Transmitter empty Clear to send, data set ready, ring indicator, or data carrier Read the modem status register detect 1 1 0 0 0 0 1 0 3 Transmitter holding register empty 0 0 0 0 4 Modem status holding Read the interrupt identification register register (if source of interrupt) or writing into the transmitter holding register line control register (LCR) The system programmer controls the format of the asynchronous data communication exchange through the LCR. In addition, the programmer is able to retrieve, inspect, and modify the contents of the LCR; this eliminates the need for separate storage of the line characteristics in system memory. The contents of this register are summarized in Table 3 and described in the following bulleted list. D Bits 0 and 1: These two bits specify the number of bits in each transmitted or received serial character. These bits are encoded as shown in Table 6. Table 6. Serial Character Word Length D 28 BIT 1 BIT 0 WORD LENGTH 0 0 5 bits 0 1 6 bits 1 0 7 bits 1 1 8 bits Bit 2: This bit specifies either one, one and one-half, or two stop bits in each transmitted character. When bit 2 is cleared, one stop bit is generated in the data. When bit 2 is set, the number of stop bits generated is dependent on the word length selected with bits 0 and 1. The receiver clocks only the first stop bit regardless of the number of stop bits selected. The number of stop bits generated in relation to word length and bit 2 are shown in Table 7. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION line control register (LCR) (continued) Table 7. Number of Stop Bits Generated D D D D D BIT 2 WORD LENGTH SELECTED BY BITS 1 AND 2 NUMBER OF STOP BITS GENERATED 0 Any word length 1 1 5 bits 1 1/2 1 6 bits 2 1 7 bits 2 1 8 bits 2 Bit 3: This bit is the parity enable bit. When bit 3 is set, a parity bit is generated in transmitted data between the last data word bit and the first stop bit. In received data, if bit 3 is set, parity is checked. When bit 3 is cleared, no parity is generated or checked. Bit 4: This bit is the even parity select bit. When parity is enabled (bit 3 is set) and bit 4 is set even parity (an even number of logic 1s in the data and parity bits) is selected. When parity is enabled and bit 4 is cleared, odd parity (an odd number of logic 1s) is selected. Bit 5: This bit is the stick parity bit. When bits 3, 4, and 5 are set, the parity bit is transmitted and checked as cleared. When bits 3 and 5 are set and bit 4 is cleared, the parity bit is transmitted and checked as set. If bit 5 is cleared, stick parity is disabled. Bit 6: This bit is the break control bit. Bit 6 is set to force a break condition; i.e., a condition where SOUT is forced to the spacing (cleared) state. When bit 6 is cleared, the break condition is disabled and has no affect on the transmitter logic; it only effects SOUT. Bit 7: This bit is the divisor latch access bit (DLAB). Bit 7 must be set to access the divisor latches of the baud generator during a read or write. Bit 7 must be cleared during a read or write to access the receiver buffer, the THR, or the IER. line status register (LSR)† The LSR provides information to the CPU concerning the status of data transfers. The contents of this register are summarized in Table 3 and described in the following bulleted list. D D Bit 0: This bit is the data ready (DR) indicator for the receiver. DR is set whenever a complete incoming character has been received and transferred into the RBR or the FIFO. DR is cleared by reading all of the data in the RBR or the FIFO. Bit 1‡: This bit is the overrun error (OE) indicator. When OE is set, it indicates that before the character in the RBR was read, it was overwritten by the next character transferred into the register. OE is cleared every time the CPU reads the contents of the LSR. If the FIFO mode data continues to fill the FIFO beyond the trigger level, an overrun error occurs only after the FIFO is full and the next character has been completely received in the shift register. An overrun error is indicated to the CPU as soon as it happens. The character in the shift register is overwritten, but it is not transferred to the FIFO. † The line status register is intended for read operations only; writing to this register is not recommended outside of a factory testing environment. ‡ Bits 1 through 4 are the error conditions that produce a receiver line status interrupt. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 29 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION line status register (LSR) (continued)† D Bit 2‡: This bit is the parity error (PE) indicator. When PE is set, it indicates that the parity of the received data character does not match the parity selected in the LCR (bit 4). PE is cleared every time the CPU reads the contents of the LSR. In the FIFO mode, this error is associated with the particular character in the FIFO to which it applies. This error is revealed to the CPU when its associated character is at the top of the FIFO. D Bit 3‡: This bit is the framing error (FE) indicator. When FE is set, it indicates that the received character did not have a valid (set) stop bit. FE is cleared every time the CPU reads the contents of the LSR. In the FIFO mode, this error is associated with the particular character in the FIFO to which it applies. This error is revealed to the CPU when its associated character is at the top of the FIFO. The ACE tries to resynchronize after a framing error. To accomplish this, it is assumed that the framing error is due to the next start bit. The ACE samples this start bit twice and then accepts the input data. D Bit 4‡: This bit is the break interrupt (BI) indicator. When BI is set, it indicates that the received data input was held low for longer than a full-word transmission time. A full-word transmission time is defined as the total time to transmit the start, data, parity, and stop bits. BI is cleared every time the CPU reads the contents of the LSR. In the FIFO mode, this error is associated with the particular character in the FIFO to which it applies. This error is revealed to the CPU when its associated character is at the top of the FIFO. When a break occurs, only one 0 character is loaded into the FIFO. The next character transfer is enabled after SIN goes to the marking state for at least two RCLK samples and then receives the next valid start bit. D D D Bit 5: This bit is the THRE indicator. THRE is set when the THR is empty, indicating that the ACE is ready to accept a new character. If the THRE interrupt is enabled when THRE is set, an interrupt is generated. THRE is set when the contents of the THR are transferred to the TSR. THRE is cleared concurrent with the loading of the THR by the CPU. In the FIFO mode, THRE is set when the transmit FIFO is empty; it is cleared when at least one byte is written to the transmit FIFO. Bit 6: This bit is the transmitter empty (TEMT) indicator. TEMT bit is set when the THR and the TSR are both empty. When either the THR or the TSR contains a data character, TEMT is cleared. In the FIFO mode, TEMT is set when the transmitter FIFO and shift register are both empty. Bit 7: In the TL16C550C mode, this bit is always cleared. In the TL16C450 mode, this bit is always cleared. In the FIFO mode, LSR7 is set when there is at least one parity, framing, or break error in the FIFO. It is cleared when the microprocessor reads the LSR and there are no subsequent errors in the FIFO. modem control register (MCR) The MCR is an 8-bit register that controls an interface with a modem, data set, or peripheral device that is emulating a modem. The contents of this register are summarized in Table 3 and are described in the following bulleted list. D D D D Bit 0: This bit (DTR) controls the DTR output. Bit 1: This bit (RTS) controls the RTS output. Bit 2: This bit (OUT1) controls OUT1, a user-designated output signal. Bit 3: This bit (OUT2) controls OUT2, a user-designated output signal. When any of bits 0 through 3 are set, the associated output is forced low. When any of these bits are cleared, the associated output is forced high. † The line status register is intended for read operations only; writing to this register is not recommended outside of a factory testing environment. ‡ Bits 1 through 4 are the error conditions that produce a receiver line status interrupt. 30 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION modem control register (MCR) (continued) D D Bit 4: This bit (LOOP) provides a local loop back feature for diagnostic testing of the ACE. When LOOP is set, the following occurs: – The transmitter SOUT is set high. – The receiver SIN is disconnected. – The output of the TSR is looped back into the receiver shift register input. – The four modem control inputs (CTS, DSR, DCD, and RI) are disconnected. – The four modem control outputs (DTR, RTS, OUT1, and OUT2) are internally connected to the four modem control inputs. – The four modem control outputs are forced to the inactive (high) levels. Bit 5: This bit (AFE) is the autoflow control enable. When set, the autoflow control as described in the detailed description is enabled. In the diagnostic mode, data that is transmitted is immediately received. This allows the processor to verify the transmit and receive data paths to the ACE. The receiver and transmitter interrupts are fully operational. The modem control interrupts are also operational, but the modem control interrupt’s sources are now the lower four bits of the MCR instead of the four modem control inputs. All interrupts are still controlled by the IER. The ACE flow can be configured by programming bits 1 and 5 of the MCR as shown in Table 8. Table 8. ACE Flow Configuration MCR BIT 5 (AFE) MCR BIT 1 (RTS) ACE FLOW CONFIGURATION 1 1 Auto-RTS and auto-CTS enabled (autoflow control enabled) 1 0 Auto-CTS only enabled 0 X Auto-RTS and auto-CTS disabled modem status register (MSR) The MSR is an 8-bit register that provides information about the current state of the control lines from the modem, data set, or peripheral device to the CPU. Additionally, four bits of this register provide change information; when a control input from the modem changes state, the appropriate bit is set. All four bits are cleared when the CPU reads the MSR. The contents of this register are summarized in Table 3 and are described in the following bulleted list. D Bit 0: This bit is the change in clear-to-send (∆ CTS) indicator. ∆ CTS indicates that the CTS input has changed state since the last time it was read by the CPU. When ∆ CTS is set (autoflow control is not enabled and the modem status interrupt is enabled), a modem status interrupt is generated. When autoflow control is enabled (∆ CTS is cleared), no interrupt is generated. D Bit 1: This bit is the change in data set ready (∆ DSR) indicator. ∆ DSR indicates that the DSR input has changed state since the last time it was read by the CPU. When ∆ DSR is set and the modem status interrupt is enabled, a modem status interrupt is generated. D Bit 2: This bit is the trailing edge of the ring indicator (TERI) detector. TERI indicates that the RI input to the chip has changed from a low to a high level. When TERI is set and the modem status interrupt is enabled, a modem status interrupt is generated. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 31 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION modem status register (MSR) (continued) D D D D D Bit 3: This bit is the change in data carrier detect (∆ DCD) indicator. ∆ DCD indicates that the DCD input to the chip has changed state since the last time it was read by the CPU. When ∆ DCD is set and the modem status interrupt is enabled, a modem status interrupt is generated. Bit 4: This bit is the complement of the clear-to-send (CTS) input. When the ACE is in the diagnostic test mode (LOOP [MCR4] = 1), this bit is equal to the MCR bit 1 (RTS). Bit 5: This bit is the complement of the data set ready (DSR) input. When the ACE is in the diagnostic test mode (LOOP [MCR4] = 1), this bit is equal to the MCR bit 0 (DTR). Bit 6: This bit is the complement of the ring indicator (RI) input. When the ACE is in the diagnostic test mode (LOOP [MCR4] = 1), this bit is equal to the MCR bit 2 (OUT1). Bit 7: This bit is the complement of the data carrier detect (DCD) input. When the ACE is in the diagnostic test mode (LOOP [MCR4] = 1), this bit is equal to the MCR bit 3 (OUT2). programmable baud generator The ACE contains a programmable baud generator that takes a clock input in the range between dc and 16 MHz and divides it by a divisor in the range between 1 and (216 –1). The output frequency of the baud generator is sixteen times (16 ×) the baud rate. The formula for the divisor is: divisor = XIN frequency input ÷ (desired baud rate × 16) Two 8-bit registers, called divisor latches, store the divisor in a 16-bit binary format. These divisor latches must be loaded during initialization of the ACE in order to ensure desired operation of the baud generator. When either of the divisor latches is loaded, a 16-bit baud counter is also loaded to prevent long counts on initial load. Tables 9 and 10 illustrate the use of the baud generator with crystal frequencies of 1.8432 MHz and 3.072 MHz respectively. For baud rates of 38.4 kbits/s and below, the error obtained is very small. The accuracy of the selected baud rate is dependent on the selected crystal frequency (refer to Figure 23 for examples of typical clock circuits). 32 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION programmable baud generator (continued) Table 9. Baud Rates Using a 1.8432-MHz Crystal DESIRED BAUD RATE DIVISOR USED TO GENERATE 16 × CLOCK PERCENT ERROR DIFFERENCE BETWEEN DESIRED AND ACTUAL 50 2304 75 1536 110 1047 0.026 134.5 857 0.058 150 768 300 384 600 192 1200 96 1800 64 2000 58 2400 48 3600 32 4800 24 7200 16 9600 12 19200 6 38400 3 56000 2 0.69 2.86 Table 10. Baud Rates Using a 3.072-MHz Crystal DESIRED BAUD RATE DIVISOR USED TO GENERATE 16 × CLOCK PERCENT ERROR DIFFERENCE BETWEEN DESIRED AND ACTUAL 50 3840 75 2560 110 1745 0.026 134.5 1428 0.034 150 1280 300 640 600 320 1200 160 1800 107 2000 96 2400 80 3600 53 4800 40 7200 27 9600 20 19200 10 38400 5 POST OFFICE BOX 655303 0.312 0.628 1.23 • DALLAS, TEXAS 75265 33 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 PRINCIPLES OF OPERATION programmable baud generator (continued) VCC Driver VCC XIN External Clock XIN C1 Crystal RP Optional Driver Optional Clock Output RX2 Oscillator Clock to Baud Generator Logic XOUT Oscillator Clock to Baud Generator Logic XOUT C2 TYPICAL CRYSTAL OSCILLATOR NETWORK RP 1 MΩ RX2 C1 C2 3.072 MHz CRYSTAL 1.5 kΩ 10 – 30 pF 40 – 60 pF 1.8432 MHz 1 MΩ 1.5 kΩ 10 – 30 pF 40 – 60 pF Figure 23. Typical Clock Circuits receiver buffer register (RBR) The ACE receiver section consists of a receiver shift register (RSR) and a RBR. The RBR is actually a 16-byte FIFO. Timing is supplied by the 16× receiver clock (RCLK). Receiver section control is a function of the ACE line control register. The ACE RSR receives serial data from SIN. The RSR then concatenates the data and moves it into the RBR FIFO. In the TL16C450 mode, when a character is placed in the RBR and the received data available interrupt is enabled (IER0 = 1), an interrupt is generated. This interrupt is cleared when the data is read out of the RBR. In the FIFO mode, the interrupts are generated based on the control setup in the FIFO control register. scratch register The scratch register is an 8-bit register that is intended for the programmer’s use as a scratchpad in the sense that it temporarily holds the programmer’s data without affecting any other ACE operation. transmitter holding register (THR) The ACE transmitter section consists of a THR and a transmitter shift register (TSR). The THR is actually a 16-byte FIFO. Timing is supplied by BAUDOUT. Transmitter section control is a function of the ACE line control register. The ACE THR receives data off the internal data bus and when the shift register is idle, moves it into the TSR. The TSR serializes the data and outputs it at SOUT. In the TL16C450 mode, if the THR is empty and the transmitter holding register empty (THRE) interrupt is enabled (IER1 = 1), an interrupt is generated. This interrupt is cleared when a character is loaded into the register. In the FIFO mode, the interrupts are generated based on the control setup in the FIFO control register. 34 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 MECHANICAL DATA FN (S-PQCC-J**) PLASTIC J-LEADED CHIP CARRIER 20 PIN SHOWN Seating Plane 0.004 (0,10) 0.180 (4,57) MAX 0.120 (3,05) 0.090 (2,29) D D1 0.020 (0,51) MIN 3 1 19 0.032 (0,81) 0.026 (0,66) 4 E 18 D2 / E2 E1 D2 / E2 8 14 0.021 (0,53) 0.013 (0,33) 0.007 (0,18) M 0.050 (1,27) 9 13 0.008 (0,20) NOM D/E D2 / E2 D1 / E1 NO. OF PINS ** MIN MAX MIN MAX MIN MAX 20 0.385 (9,78) 0.395 (10,03) 0.350 (8,89) 0.356 (9,04) 0.141 (3,58) 0.169 (4,29) 28 0.485 (12,32) 0.495 (12,57) 0.450 (11,43) 0.456 (11,58) 0.191 (4,85) 0.219 (5,56) 44 0.685 (17,40) 0.695 (17,65) 0.650 (16,51) 0.656 (16,66) 0.291 (7,39) 0.319 (8,10) 52 0.785 (19,94) 0.795 (20,19) 0.750 (19,05) 0.756 (19,20) 0.341 (8,66) 0.369 (9,37) 68 0.985 (25,02) 0.995 (25,27) 0.950 (24,13) 0.958 (24,33) 0.441 (11,20) 0.469 (11,91) 84 1.185 (30,10) 1.195 (30,35) 1.150 (29,21) 1.158 (29,41) 0.541 (13,74) 0.569 (14,45) 4040005 / B 03/95 NOTES: A. All linear dimensions are in inches (millimeters). B. This drawing is subject to change without notice. C. Falls within JEDEC MS-018 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 35 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 MECHANICAL DATA N (R-PDIP-T**) PLASTIC DUAL-IN-LINE PACKAGE 24 PIN SHOWN A 24 13 0.560 (14,22) 0.520 (13,21) 1 12 0.060 (1,52) TYP 0.200 (5,08) MAX 0.610 (15,49) 0.590 (14,99) 0.020 (0,51) MIN Seating Plane 0.100 (2,54) 0.021 (0,53) 0.015 (0,38) 0.125 (3,18) MIN 0.010 (0,25) M PINS ** 0°– 15° 0.010 (0,25) NOM 24 28 32 40 48 52 A MAX 1.270 (32,26) 1.450 (36,83) 1.650 (41,91) 2.090 (53,09) 2.450 (62,23) 2.650 (67,31) A MIN 1.230 (31,24) 1.410 (35,81) 1.610 (40,89) 2.040 (51,82) 2.390 (60,71) 2.590 (65,79) DIM 4040053 / B 04/95 NOTES: A. B. C. D. 36 All linear dimensions are in inches (millimeters). This drawing is subject to change without notice. Falls within JEDEC MS-011 Falls within JEDEC MS-015 (32 pin only) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 MECHANICAL DATA PFB (S-PQFP-G48) PLASTIC QUAD FLATPACK 0,27 0,17 0,50 36 0,08 M 25 37 24 48 13 0,13 NOM 1 12 5,50 TYP 7,20 SQ 6,80 9,20 SQ 8,80 Gage Plane 0,25 0,05 MIN 0°– 7° 1,05 0,95 Seating Plane 0,75 0,45 0,08 1,20 MAX 4073176 / B 10/96 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. Falls within JEDEC MS-026 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 37 TL16C550C, TL16C550CI ASYNCHRONOUS COMMUNICATIONS ELEMENT WITH AUTOFLOW CONTROL SLLS177F – MARCH 1994 – REVISED MARCH 2001 MECHANICAL DATA PT (S-PQFP-G48) PLASTIC QUAD FLATPACK 0,27 0,17 0,50 36 0,08 M 25 37 24 48 13 0,13 NOM 1 12 5,50 TYP 7,20 SQ 6,80 9,20 SQ 8,80 Gage Plane 0,25 0,05 MIN 1,45 1,35 Seating Plane 1,60 MAX 0°– 7° 0,75 0,45 0,10 4040052 / C 11/96 NOTES: A. B. C. D. 38 All linear dimensions are in millimeters. This drawing is subject to change without notice. Falls within JEDEC MS-026 This may also be a thermally enhanced plastic package with leads conected to the die pads. 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