PKP
VS1000 P
ROGRAMMER
’
S
G
UIDE
VSMPG
17.4
Timing
Figure 16. shows the signal generation for the command write operation when wait
states is 1. The write pulse duration can be calculated from equation:
T wl
= 1
/f
CLKI
∗
(
W S
+ 1)
, where
CLKI is the internal clock frequency and WS is the nand flash IF wait state register.
Same principle applies to NFDIO signals.
Nand Flash Command Write Transaction
Sym
Parameter
CLKI cyc
Min@48MHz
Max@48MHz
T
cles
Command latch enable setup
time
> 1
41.6ns
T
cleh
Command latch enable setup
time
> 1
41.6ns
T
cled
ALE inactive to CLE active
delay
> 1
41.6ns
T
ces
NFCE active to NFWR active
delay
1
20.8ns
20.8ns
T
ceh
NFWR inactive to NFCE inac-
tive delay
1
20.8ns
20.8ns
T
wl
Write enable low time
1+WS
41.6ns
T
wh
Write enable high time
1+WS
41.6ns
T
dos
NFDIO data out setup time
1+WS
41.6ns
T
doh
NFDIO data out hold time
1+WS
41.6ns
Figure 16: Nand Flash IF Command Write, WaitStates = 1
Rev. 0.20
2011-10-04
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