SMJ55161 View Datasheet(PDF) - Austin Semiconductor

Part Name

Description

Manufacturer

SMJ55161

262144 BY 16-BIT MULTIPORT VIDEO RAM

Austin Semiconductor 

SMJ55161

262144 BY 16-BIT

MULTIPORT VIDEO RAM

SGMS056D – MAY 1995 – REVISED OCTOBER 1997

serial enable (SE)

During serial-access operations, SE is used as an enable / disable for the SQ outputs. SE low enables the

serial-data output while SE high disables the serial-data output. SE is also used as an enable / disable for output

pin QSF.

IMPORTANT: While SE is held high, the serial clock is not disabled. External SC pulses increment the internal

serial-address counter regardless of the state of SE. This ungated serial-clock scheme minimizes access time

of serial output from SE low because the serial-clock input buffer and the serial-address counter are not disabled

by SE.

special-function output (QSF)

QSF is an output pin that indicates which half of the SAM is being accessed. When QSF is low, the serial-address

pointer is accessing the lower (least significant) 128 bits of the serial register (SAM). When QSF is high, the

pointer is accessing the higher (most significant) 128 bits of the SAM.

During full-register-transfer operations, QSF can change state upon completing the cycle. This state is

determined by the tap point loaded during the transfer cycle. QSF is enabled by SE; therefore, if SE is high, the

QSF output is in the high-impedance state.

no connect / ground (NC / GND)

NC/ GND must be tied to system ground or left floating for proper device operation.

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