Datasheet

SN54ALS652, SN54ALS653, SN54AS651, SN54AS652
SN74ALS651A, SN74ALS652A, SN74ALS653, SN74ALS654, SN74AS651, SN74AS652
OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS
SDAS066G – DECEMBER 1983 – REVISED DECEMBER 2000
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
Function Tables
SN54ALS653, SN54AS651,
SN74ALS651A, SN74ALS653, SN74AS651
INPUTS
DATA I/O
†
OPERATION OR FUNCTION
OEAB OEBA CLKAB CLKBA SAB SBA A1–A8 B1–B8
OPERATION
OR
FUNCTION
L H H or L H or L X X Input Input Isolation
L H ↑↑X X Input Input Store A and B data
X H ↑ H or L X X Input Unspecified
‡
Store A, hold B
H H ↑↑X
‡
X Input Output Store A in both registers
L X H or L ↑ X X Unspecified
‡
Input Hold A, store B
L L ↑↑XX
‡
Output Input Store B in both registers
L L X X X L Output Input Real-time B data to A bus
L L X H or L X H Output Input Stored B data to A bus
H H X X L X Input Output Real-time A data to B bus
H H H or L X H X Input Output Stored A data to B bus
H L H or L H or L H H Output Output
Stored A data to B bus and
stored B
data to A bus
†
The data output functions can be enabled or disabled by a variety of level combinations at OEAB or OEBA
. Data input functions always are
enabled; i.e., data at the bus terminals is stored on every low-to-high transition on the clock inputs.
‡
Select control = L: clocks can occur simultaneously.
Select control = H: clocks must be staggered to load both registers.
SN54ALS652, SN54AS652,
SN74ALS652A, SN74ALS654, SN74AS652
INPUTS
DATA I/O
†
OPERATION OR FUNCTION
OEAB OEBA CLKAB CLKBA SAB SBA A1–A8 B1–B8
OPERATION
OR
FUNCTION
L H H or L H or L X X Input Input Isolation
L H ↑↑X X Input Input Store A and B data
X H ↑ H or L X X Input Unspecified
‡
Store A, hold B
H H ↑↑X
‡
X Input Output Store A in both registers
L X H or L ↑ X X Unspecified
‡
Input Hold A, store B
L L ↑↑XX
‡
Output Input Store B in both registers
L L X X X L Output Input Real-time B data to A bus
L L X H or L X H Output Input Stored B data to A bus
H H X X L X Input Output Real-time A data to B bus
H H H or L X H X Input Output Stored A data to B bus
H L H or L H or L H H Output Output
Stored A data to B bus and
stored B data to A bus
†
The data output functions can be enabled or disabled by a variety of level combinations at OEAB or OEBA
. Data input functions always are
enabled; i.e., data at the bus terminals is stored on every low-to-high transition on the clock inputs.
‡
Select control = L: clocks can occur simultaneously.
Select control = H: clocks must be staggered to load both registers.