SMJ44C251 Datasheet, PDF (50/53 Pages) Texas Instruments – 262144 BY 4-BIT MULTIPORT VIDEO RAM

SMJ44C251B
262144 BY 4-BIT
MULTIPORT VIDEO RAM
SGMS058A – MARCH 1995 – REVISED JUNE 1995
PARAMETER MEASUREMENT INFORMATION
RAS
TRG
SC
tsu( _TRG)
tw(SCH)
tc(SC)
tw(SCL)
ta(SQ)
th(SHSQ)
th(SHSQ)
th( _TRG)
tc(SC)
tw(SCH)
tw(SCL)
tw(SCH)
ta(SQ)
th(SHSQ)
ta(SQ)
SDQ0 – SDQ3
Valid Out
Valid Out
Valid Out
Valid Out
NOTES: A. While reading data through the serial-data register, the state of TRG is a don’t care as long as TRG is held high when RAS goes
low. This is to avoid the initiation of a register-to-memory-to-register data-transfer operation.
B. The serial data-out cycle is used to read data out of the data registers. Before data can be read via SDQ, the device must be put
into the read mode by performing a transfer-read cycle. Any transfer-write cycles occurring between the transfer-read cycle and the
subsequent shifting out of data take the device out of the read mode and put it in the write mode, not allowing the reading of data.
Figure 38. Serial-Read-Cycle Timing (SE = V_IL )
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