Oki ML420 Maintenance Manual page 12

(3) RAM
The RAM is CMOS dynamic RAM with 256K × 16-bit (4Mbit), 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.
* Clockout is provided when the original excitation is selected.
42113901TH01 Rev.3
MPU
P03
CAS-N
CS1
WRH-N
P11
WRL-N
WRL
D0~D15
RD
Clockout* T1
A0~A8
RAS-N
VCAS-N
LCAS-N
RD-N
D0~D15
(Read)
WR-N
D0~D7
(Write)
16-bit bus, Word instruction
RAM
A0~A8
RAS-N
RAS
UCAS-N
UCAS
ALS139
LCAS-N
LCAS
WR-N
ALS11
WE
RD-N
OE
T2 T3 T4
Oki Data CONFIDENTIAL
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