SDAS226A - DECEMBER 1982 - REVISED JANUARY 1995
These octal bus transceivers are designed for asynchronous two-waycommunication between data buses. The control-function implementationallows for maximum flexibility in timing.
These devices allow data transmission from the A bus to the B busor from the B bus to the A bus, depending upon the logic levels atthe output-enable (OEAB and 
)inputs.
The output-enable inputs disable the device so that the buses areeffectively isolated. The dual-enable configuration gives thetransceivers the capability to store data by simultaneously enablingOEAB and . Each outputreinforces its input in this transceiver configuration. When bothOEAB and are enabledand all other data sources to the two sets of bus lines are in thehigh-impedance state, both sets of bus lines (16 total) remain attheir last states. The 8-bit codes appearing on the two sets of busesare identical for the SN74ALS621A, SN74ALS623A, and SN74AS623 orcomplementary for the SN74ALS620A.
The -1 versions of the SN74ALS620A and SN74ALS621A are identicalto the standard versions, except that the recommended maximumIOL is increased to 48 mA in the -1 versions.
The SN74ALS620A, SN74ALS621A, SN74ALS623A, and SN74AS623 arecharacterized for operation from 0°C to 70°C.
View more information about generic part numbers:SN74ALS620A, SN74ALS621A, SN74ALS621A-1, SN74ALS623A, SN74AS623
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