Example Of Memory Expansion - Renesas 7700 FAMILY User Manual

APPLICATIONS
17.1 Memory expansion

17.1.4 Example of memory expansion

(1) Example of SRAM expansion (minimum model)
Figure 17.1.21 shows a memory expansion example (minimum model) using a 32-Kbyte SRAM in the
memory expansion mode at the low-speed running. Figure 17.1.22 shows the timing chart for this
example.
Figure 17.1.23 shows a memory expansion example (minimum model) using a 32-Kbyte SRAM in the
memory expansion mode at the high-speed running. Figure 17.1.24 shows the timing chart for this
example.
M37751
BYTE
A
14
CNV
SS
A –A
0 13
D –D
0 7
BHE
E
R/W
X X
IN OUT
25 MHz
Fig. 17.1.21 Example of SRAM expansion (minimum model at low-speed running)
17–26
M5M5256CP-70LL
1
AC32
S
A –A
0
A
14
D –D
0
OE
Open
2
AC32
Circuit condition : 3 access in low-speed running
7751 Group User's Manual
1, 2: Use the elements of which propagation
delay time is within 18 ns.
13
7
0000
16
WE
0080
16
0880
16
4000
16
FFFF
16
Memory map
SFR area
Internal RAM area
External RAM
area
(M5M5256CP)
Internal ROM area