Oki 3391 Printer User Manual


 
2 – 4
(3) RAM (MSM51C464A-80RS)
The RAM is CMOS dynamic RAM with (64K × 4-bit) × 2 configuration, and used as buffers
(such as receiving buffer, printing buffer, DLL buffer and working buffer).
The following shows the examples of the memory access operation.
A0~A7
RAM 1 (Q3)MPU
P03
CS1
RD
OE
D4~D7
D0~D3
RAS
CAS
RAM 2 (Q4)
T1 T2 T3
Clockout*
A0~A7
CS1~CS4
RD
D0~D7
(Read)
WRH
WRL
D0~D7
(Write)
8-bit bus, byte instruction
* Clockout is provided when the original excitation is selected.