Datasheet Texas Instruments SN74ALS561AN — Datenblatt

SN54ALS561A, SN74ALS561A
SYNCHRONOUS 4-BIT COUNTERS
WITH 3-STATE OUTPUTS
SDAS225A – DECEMBER 1982 – REVISED JANUARY 1995 description
These binary counters are programmable and
offer synchronous and asynchronous clearing as
well as synchronous and asynchronous loading.
All synchronous functions are executed on the
positive-going edge of the clock.
The clear function is initiated by applying a low
level to either asynchronous clear (ACLR) or
synchronous clear (SCLR). ACLR (direct clear)
overrides all other functions of the device, while
SCLR overrides only the other synchronous
functions. Data is loaded from the A, B, C, and D
inputs by applying a low level to asynchronous
load (ALOAD) or by the combination of a low level
at synchronous load (SLOAD) and a
positive-going clock transition. The counting
function is enabled only when enable P (ENP),
enable T (ENT), ACLR, ALOAD, SCLR, and
SLOAD are all high. ALOAD
CLK …