7733 Datasheet, PDF (765/940 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER

LOW VOLTAGE VERSION
18.6 Applications
18.6.3 Ready generating circuit example
When validating “wait” only for a certain area (for example, ROM area) in Figure 18.6.3, use the ready
function.
Figure 18.6.5 shows a ready generating circuit example.
M37735MHLXXXHP
CS0
RSMP
CS0
AC32
RDY
1
Wait generated by the ready function is
inserted only to an area where
accessed by signal CS 0.
Circuit conditions : f(X IN) ≤ 12 MHz, no wait,
1=
f(XIN)
2
,
f(XIN)
8
,
f(XIN)
16
,
or
f(XCIN)
2
td(RDE- 1)
tc
RDE
CS0
td(RSMP-RDE)
RSMP
RDY
Propagation delay
time of AC32
(max. : 28 ns)
V
tsu(RDY- 1)
: Wait generated by the ready function
V Condition to satisfy the relationship tsu(RDY- 1) ≥ 80 ns is
tc+td(RSMP-RDE) ≥ 108 ns
Accordingly, when f (XIN) ≤ 12 MHz, this
example satisfies the relationship tsu(RDY- 1) ≥ 80 ns.
Fig. 18.6.5 Ready generating circuit example
7735 Group User’s Manual
18-17