UPD784218 Datasheet, PDF (51/92 Pages) NEC – 16-/8-BIT SINGLE-CHIP MICROCONTROLLERS

µPD784218, 784218Y
10. LOCAL BUS INTERFACE
The local bus interface can connect an external memory or I/O (memory mapped I/O) and support a memory
space of 1 MB (refer to Figure 10-1).
Figure 10-1. Example of Local Bus Interface
(a) Multiplexed bus mode
µPD784218
RD
WR
A8 to A19
ASTB
AD0 to AD7
VDD
Address latch
LE
Q0 to Q7
D0 to D7
OE
Address bus
SRAM
CS
OE
WE
I/O1 to I/O8
A0 to A19
Data bus
µPD784218
RD
WR
A0 to A19
AD0 to AD7
(b) Separate bus mode
VDD
SRAM
CS
Address bus
OE
WE
I/O1 to I/O8
A0 to A19
Data bus
Data Sheet U12304EJ2V0DS00
51