SMJ44C251B Datasheet, PDF (29/57 Pages) Texas Instruments – 262144 BY 4-BIT MULTIPORT VIDEO RAM

VRAM
SMJ44C251B
Austin Semiconductor, Inc.
MT42C4256
FIGURE 19: Enhanced-Page-Mode
Read-Modify-Write-Cycle Timing
NOTES:
1. Output can go from the high-impedance state to an invalid data state prior to the specified access time.
NOTE C: A read or a write cycle can be intermixed with read-modify-write cycles as long as the read and write timing specifications are not violated.
WRITE-CYCLE STATE TABLE
CYCLE
Write Operation
Write-mask load/use, Write DQs to I/Os
Use previous write mask, Write DQs to I/Os
Load write mask on later of W\ fall and CAS\ fall
SMJ44C251B/MT42C4256
Rev. 0.1 12/03
1
L
L
H
H
29
STATE
2
3
4
5
L
H
Don't Care Valid Data
L
L Write Mask Valid Data
L
L
Don't Care Valid Data
L
H
Don't Care Write Mask
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.