SMJ44C251B Datasheet, PDF (46/57 Pages) Texas Instruments – 262144 BY 4-BIT MULTIPORT VIDEO RAM

Austin Semiconductor, Inc.
VRAM
SMJ44C251B
MT42C4256
FIGURE 36: Serial-Write-Cycle Timing (SE\ = V_IL)
NOTES:
NOTE S: The serial data-in cycle is used to input serial data into the data registers. Before data can be written into the data registers via the SDQ
terminals, the device must be put into the write mode by performing a write-mode-control (pseudo-transfer) cycle or any other write-transfer cycle.
A read-transfer cycle is the only cycle that takes the serial port (SAM) out of the write mode and puts it into the read mode, disabling the input data.
Data is written starting at the location specified by the input address loaded on the previous transfer cycle.
NOTE T: While accessing data in the serial-data registers, the state of TRG\ is a don’t care as long as TRG\ is held high when RAS\ goes low to prevent
data transfers between memory and data registers.
SMJ44C251B/MT42C4256
Rev. 0.1 12/03
46
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