Texas Instruments

The SN54ABT16541 and SN74ABT16541A are noninverting 16-bit buffers composed of two 8-bit sections with separate output-enable signals. For either 8-bit buffer section, the two output-enable (1and 1or 2and 2) inputs must both be low for the corresponding Y outputs to be active. If either output-enable input is high, the outputs of that 8-bit buffer section are in the high-impedance state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16541 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16541A is characterized for operation from -40°C to 85°C. The SN54ABT16541 and SN74ABT16541A are noninverting 16-bit buffers composed of two 8-bit sections with separate output-enable signals. For either 8-bit buffer section, the two output-enable (1and 1or 2and 2) inputs must both be low for the corresponding Y outputs to be active. If either output-enable input is high, the outputs of that 8-bit buffer section are in the high-impedance state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16541 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16541A is characterized for operation from -40°C to 85°C.

These 18-bit universal bus transceivers combine D-type latches and D-type flip-flops to allow data flow in transparent, latched, clocked, and clock-enabled modes. Data flow in each direction is controlled by output-enable (and), latch-enable (LEAB and LEBA), and clock (CLKAB and CLKBA) inputs. The clock can be controlled by the clock-enable (and) inputs. For A-to-B data flow, the device operates in the transparent mode when LEAB is high. When LEAB is low, the A data is latched if CLKAB is held at a high or low logic level. If LEAB is low, the A data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. Output enableis active low. Whenis low, the outputs are active. Whenis high, the outputs are in the high-impedance state. Data flow for B to A is similar to that of A to B, but uses, LEBA, CLKBA, and. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16601 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16601 is characterized for operation from -40°C to 85°C. These 18-bit universal bus transceivers combine D-type latches and D-type flip-flops to allow data flow in transparent, latched, clocked, and clock-enabled modes. Data flow in each direction is controlled by output-enable (and), latch-enable (LEAB and LEBA), and clock (CLKAB and CLKBA) inputs. The clock can be controlled by the clock-enable (and) inputs. For A-to-B data flow, the device operates in the transparent mode when LEAB is high. When LEAB is low, the A data is latched if CLKAB is held at a high or low logic level. If LEAB is low, the A data is stored in the latch/flip-flop on the low-to-high transition of CLKAB. Output enableis active low. Whenis low, the outputs are active. Whenis high, the outputs are in the high-impedance state. Data flow for B to A is similar to that of A to B, but uses, LEBA, CLKBA, and. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16601 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16601 is characterized for operation from -40°C to 85°C.

The 'ABT16623 are 16-bit transceivers designed for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The 'ABT16623 provide true data at the outputs. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. They allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and) inputs. The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and. Each output reinforces its input in this configuration. When both OEAB andare enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (32 total) remain at their last states. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver. The SN54ABT16623 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16623 is characterized for operation from -40°C to 85°C. The 'ABT16623 are 16-bit transceivers designed for asynchronous communication between data buses. The control-function implementation allows for maximum flexibility in timing. The 'ABT16623 provide true data at the outputs. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. They allow data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic levels at the output-enable (OEAB and) inputs. The output-enable inputs can be used to disable the device so that the buses are effectively isolated. The dual-enable configuration gives the transceivers the capability of storing data by simultaneously enabling OEAB and. Each output reinforces its input in this configuration. When both OEAB andare enabled and all other data sources to the two sets of bus lines are at high impedance, both sets of bus lines (32 total) remain at their last states. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. OEAB should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver. The SN54ABT16623 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16623 is characterized for operation from -40°C to 85°C.

The 'ABT16640 are inverting 16-bit transceivers designed for asynchronous communication between data buses. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. It allows data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (1DIR and 2DIR) inputs. The output-enable (1and 2) inputs can be used to disable the device so that the buses are effectively isolated. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16640 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16640 is characterized for operation from -40°C to 85°C. The 'ABT16640 are inverting 16-bit transceivers designed for asynchronous communication between data buses. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. It allows data transmission from the A bus to the B bus or from the B bus to the A bus, depending on the logic level at the direction-control (1DIR and 2DIR) inputs. The output-enable (1and 2) inputs can be used to disable the device so that the buses are effectively isolated. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16640 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16640 is characterized for operation from -40°C to 85°C.

The 'ABT16646 devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal registers. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Data on the A or B bus is clocked into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT16646 devices. Output-enable (OE\) and direction-control (DIR) inputs are provided to control the transceiver functions. In the transceiver mode, data present at the high-impedance port may be stored in either register or in both. The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. The direction control (DIR) determines which bus receives data when OE\ is low. In the isolation mode (OE\ high), A data can be stored in one register and/or B data can be stored in the other register. When an output function is disabled, the input function is still enabled and can be used to store and transmit data. Only one of the two buses, A or B, can be driven at a time. To ensure the high-impedance state during power up or power down, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16646 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16646 is characterized for operation from -40°C to 85°C. The 'ABT16646 devices consist of bus-transceiver circuits, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the input bus or from the internal registers. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Data on the A or B bus is clocked into the registers on the low-to-high transition of the appropriate clock (CLKAB or CLKBA) input. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT16646 devices. Output-enable (OE\) and direction-control (DIR) inputs are provided to control the transceiver functions. In the transceiver mode, data present at the high-impedance port may be stored in either register or in both. The select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) data. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. The direction control (DIR) determines which bus receives data when OE\ is low. In the isolation mode (OE\ high), A data can be stored in one register and/or B data can be stored in the other register. When an output function is disabled, the input function is still enabled and can be used to store and transmit data. Only one of the two buses, A or B, can be driven at a time. To ensure the high-impedance state during power up or power down, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16646 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16646 is characterized for operation from -40°C to 85°C.

The 'ABT16652 are 16-bit bus transceivers that consist of D-type flip-flops and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Output-enable (OEAB and) inputs are provided to control the transceiver functions. Select-control (SAB and SBA) inputs are provided to select whether real-time or stored data is transferred. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. A low input selects real-time data, and a high input selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT16652. Data on the A- or B-data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs regardless of the select- or enable-control inputs. When SAB and SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and. In this configuration, each output reinforces its input. When all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remains at its last state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver (A to B). The SN54ABT16652 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16652 is characterized for operation from -40°C to 85°C. The 'ABT16652 are 16-bit bus transceivers that consist of D-type flip-flops and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. These devices can be used as two 8-bit transceivers or one 16-bit transceiver. Output-enable (OEAB and) inputs are provided to control the transceiver functions. Select-control (SAB and SBA) inputs are provided to select whether real-time or stored data is transferred. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. A low input selects real-time data, and a high input selects stored data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ABT16652. Data on the A- or B-data bus, or both, can be stored in the internal D-type flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs regardless of the select- or enable-control inputs. When SAB and SBA are in the real-time transfer mode, it is possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and. In this configuration, each output reinforces its input. When all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remains at its last state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver (B to A). OEAB should be tied to GND through a pulldown resistor; the minimum value of the resistor is determined by the current-sourcing capability of the driver (A to B). The SN54ABT16652 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16652 is characterized for operation from -40°C to 85°C.

The 'ABT16657 contain two noninverting octal transceiver sections with separate parity generator/checker circuits and control signals. For either section, the transmit/receive (1T/R\ or 2T/R\) input determines the direction of data flow. When 1T/R\ (or 2T/R\) is high, data flows from the 1A (or 2A) port to the 1B (or 2B) port (transmit mode); when 1T/R\ (or 2T/R\) is low, data flows from the 1B (or 2B) port to the 1A (or 2A) port (receive mode). When the output-enable (1or 2) input is high, both the 1A (or 2A) and 1B (or 2B) ports are in the high-impedance state. Odd or even parity is selected by a logic high or low level, respectively, on the 1ODD(or 2ODD) input. 1PARITY (or 2PARITY) carries the parity bit value; it is an output from the parity generator/checker in the transmit mode and an input to the parity generator/checker in the receive mode. In the transmit mode, after the 1A (or 2A) bus is polled to determine the number of high bits, 1PARITY (or 2PARITY) is set to the logic level that maintains the parity sense selected by the level at the 1ODD(or 2ODD) input. For example, if 1ODDis low (even parity selected) and there are five high bits on the 1A bus, then 1PARITY is set to the logic high level so that an even number of the nine total bits (eight 1A-bus bits plus parity bit) are high. In the receive mode, after the 1B (or 2B) bus is polled to determine the number of high bits, the 1(or 2) output logic level indicates whether or not the data to be received exhibits the correct parity sense. For example, if 1ODDis high (odd parity selected), 1PARITY is high, and there are three high bits on the 1B bus, then 1is low, indicating a parity error. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16657 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16657 is characterized for operation from -40°C to 85°C. The 'ABT16657 contain two noninverting octal transceiver sections with separate parity generator/checker circuits and control signals. For either section, the transmit/receive (1T/R\ or 2T/R\) input determines the direction of data flow. When 1T/R\ (or 2T/R\) is high, data flows from the 1A (or 2A) port to the 1B (or 2B) port (transmit mode); when 1T/R\ (or 2T/R\) is low, data flows from the 1B (or 2B) port to the 1A (or 2A) port (receive mode). When the output-enable (1or 2) input is high, both the 1A (or 2A) and 1B (or 2B) ports are in the high-impedance state. Odd or even parity is selected by a logic high or low level, respectively, on the 1ODD(or 2ODD) input. 1PARITY (or 2PARITY) carries the parity bit value; it is an output from the parity generator/checker in the transmit mode and an input to the parity generator/checker in the receive mode. In the transmit mode, after the 1A (or 2A) bus is polled to determine the number of high bits, 1PARITY (or 2PARITY) is set to the logic level that maintains the parity sense selected by the level at the 1ODD(or 2ODD) input. For example, if 1ODDis low (even parity selected) and there are five high bits on the 1A bus, then 1PARITY is set to the logic high level so that an even number of the nine total bits (eight 1A-bus bits plus parity bit) are high. In the receive mode, after the 1B (or 2B) bus is polled to determine the number of high bits, the 1(or 2) output logic level indicates whether or not the data to be received exhibits the correct parity sense. For example, if 1ODDis high (odd parity selected), 1PARITY is high, and there are three high bits on the 1B bus, then 1is low, indicating a parity error. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16657 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16657 is characterized for operation from -40°C to 85°C.

These 20-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers. The 'ABT16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The 20 flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the device provides true data at the Q outputs. A buffered output-enable () input can be used to place the ten outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16821 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16821 is characterized for operation from -40°C to 85°C. These 20-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers. The 'ABT16821 can be used as two 10-bit flip-flops or one 20-bit flip-flop. The 20 flip-flops are edge-triggered D-type flip-flops. On the positive transition of the clock (CLK) input, the device provides true data at the Q outputs. A buffered output-enable () input can be used to place the ten outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. To ensure the high-impedance state during power up or power down,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16821 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16821 is characterized for operation from -40°C to 85°C.

These 18-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers. The 'ABT16823 can be used as two 9-bit flip-flops or one 18-bit flip-flop. With the clock-enable () input low, the D-type flip-flops enter data on the low-to-high transitions of the clock. Takinghigh disables the clock buffer, latching the outputs. Taking the clear () input low causes the Q outputs to go low independently of the clock. A buffered output-enable () input can be used to place the nine outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. When VCCis between 0 and 2.1 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 2.1 V,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking/current-sourcing capability of the driver. The SN54ABT16823 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16823 is characterized for operation from -40°C to 85°C. These 18-bit flip-flops feature 3-state outputs designed specifically for driving highly capacitive or relatively low-impedance loads. They are particularly suitable for implementing wider buffer registers, I/O ports, bidirectional bus drivers with parity, and working registers. The 'ABT16823 can be used as two 9-bit flip-flops or one 18-bit flip-flop. With the clock-enable () input low, the D-type flip-flops enter data on the low-to-high transitions of the clock. Takinghigh disables the clock buffer, latching the outputs. Taking the clear () input low causes the Q outputs to go low independently of the clock. A buffered output-enable () input can be used to place the nine outputs in either a normal logic state (high or low logic level) or a high-impedance state. In the high-impedance state, the outputs neither load nor drive the bus lines significantly. The high-impedance state and increased drive provide the capability to drive bus lines without need for interface or pullup components. does not affect the internal operation of the flip-flops. Old data can be retained or new data can be entered while the outputs are in the high-impedance state. When VCCis between 0 and 2.1 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 2.1 V,should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking/current-sourcing capability of the driver. The SN54ABT16823 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16823 is characterized for operation from -40°C to 85°C.

The 'ABT16827 are noninverting 20-bit buffers composed of two 10-bit sections with separate output-enable signals. For either 10-bit buffer section, the two output-enable (1OE1\ and 1OE2\ or 2OE1\ and 2OE2\) inputs must both be low for the corresponding Y outputs to be active. If either output-enable input is high, the outputs of that 10-bit buffer section are in the high-impedance state. When VCCis between 0 and 2.1 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 2.1 V, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16827 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16827 is characterized for operation from -40°C to 85°C. The 'ABT16827 are noninverting 20-bit buffers composed of two 10-bit sections with separate output-enable signals. For either 10-bit buffer section, the two output-enable (1OE1\ and 1OE2\ or 2OE1\ and 2OE2\) inputs must both be low for the corresponding Y outputs to be active. If either output-enable input is high, the outputs of that 10-bit buffer section are in the high-impedance state. When VCCis between 0 and 2.1 V, the device is in the high-impedance state during power up or power down. However, to ensure the high-impedance state above 2.1 V, OE\ should be tied to VCCthrough a pullup resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver. The SN54ABT16827 is characterized for operation over the full military temperature range of -55°C to 125°C. The SN74ABT16827 is characterized for operation from -40°C to 85°C.