Renesas 7700 FAMILY User Manual page 368

Table 17.1.1 Memory expansion model
Access area
External data
bus width
8-bit width;
BYTE = "H"
BYTE
16-bit width;
BYTE = "L"
Notes 1: Refer to "Chapter 12. CONNECTION WITH EXTERNAL DEVICES" for details about the functions and operation
of used pins when expanding a memory. Refer to "Chapter 15. ELECTRICAL CHARACTERISTICS" for timing
requirements.
2: Because the address bus width is used as maximum 24 bits when expanding a memory, strengthen the M37751's
Vss line. (Refer to "Appendix 8. Examples of noise immunity improvement.")
Maximum 64 Kbytes
M37751
BYTE
16
P0
P1
8
P2
Memory expansion model
M37751
P0
Latch
8
P1
D Q
E
P2
16
ALE
BHE
Memory expansion model
7751 Group User's Manual
M37751
BYTE
A –A
0 15
D –D
0 7
Memory expansion model
Minimum model
M37751
16
BYTE
A –A
0 15
D –D
0 15
Memory expansion model
Medium model B
APPLICATIONS
17.1 Memory expansion
Maximum 16 Mbytes
16+n
P0
P1
Latch
n
P2
D Q
E
ALE
8
Medium model A
16+n
P0
Latch
8
D Q
P1
E
n
P2 D Q
E
16
ALE
Latch
BHE
Maximum model
A –A
0 15+n
D –D
0 7
A –A
0 15+n
D –D
0 15
17–3