Accessing Expansion Data Memory - NEC PD78212 User Manual

Fig. 13-5 Accessing Expansion Data Memory
A16-A19
(output)
A8-A15
(output)
Lower
Hi-Z
AD0-AD7
address
(output)
ASTB (output)
RD (output)
A16-A19
(output)
A8-A15
(output)
Lower
Hi-Z
AD0-AD7
address
(output)
ASTB (output)
RD (output)
WR (output)
(a) Read cycle
Fetch cycle Expansion data memory access cycle
Higher address
Lower
Hi-Z Hi-Z
Program
address
(input)
(output)
(b) Write cycle
Fetch cycle Expansion data memory access cycle
Higher address
Lower
Hi-Z Hi-Z
Program
address
(input)
(output)
Chapter 13 Local Bus Interface Function
Contents of P6/PM6 register
Higher address
Hi-Z Hi-Z
Data
(input)
Contents of P6/PM6 register
Higher address
Hi-Z
Data (input)
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