
May 3, 2004 pSRAM_Type02_15A0
Type 2 pSRAM
107
A d v a n c e I n f o r m a t i o n
Notes:
1. A write occurs during the overlap(t
WP
) of low CS1# and low WE#. A write begins when CS1# goes low and WE# goes low
with asserting UB# or LB# for single byte operation or simultaneously asserting UB# and LB# for double byte operation. A
write ends at the earliest transition when CS1# goes high and WE# goes high. The t
WP
is measured from the beginning of
write to the end of write.
2. t
CW
is measured from the CS1# going low to the end of write.
3. t
AS
is measured from the address valid to the beginning of write.
4. t
WR
is measured from the end of write to the address change. t
WR
is applied in case a write ends with CS1# or WE# going
high.
Figure 31. Timing Waveform of Write Cycle(3) (CS2 Controlled)
Figure 32. Timing Waveform of Write Cycle(4) (UB#, LB# Controlled)
Address
Data Valid
UB#, LB#
WE#
Data in
Data out
High-Z
t
WC
t
CW
t
AW
t
BW
t
WP(1)
t
DH
t
DW
t
WR
t
AS
CS1#
CS2
Address
Data Valid
UB#, LB#
WE#
Data in
Data out
High-Z
t
WC
t
CW
t
BW
t
WP
t
DH
t
DW
t
WR
t
AW
t
AS
CS1#
CS2