NEC PD78055 Benutzerhandbuch
523
CHAPTER 22 EXTERNAL DEVICE EXPANSION FUNCTION
µ
PD43256B
CS
OE
A0-A14
I/O1-I/O8
WE
Address
Bus
Bus
V
DD
µ
PD78054
µ
PD74HC573
LE
D0-D7
Q0-Q7
OE
RD
WR
A8-A14
ASTB
AD0-AD7
Data
Bus
Bus
V
DD
22.4 Example of Connection with Memory
This section provides
µ
PD78054 and external memory connection examples in Figure 22-8. SRAMs are used as
the external memory in these diagrams. In addition, the external device expansion function is used in the full-address
mode, and the address from 0000H to 7FFFH (32 Kbytes) are allocated for internal ROM, and the addresses after
8000H for SRAM.
Figure 22-8. Connection Example of
µ
PD78054 and Memory