Oki MICROLINE 320 Turbo Maintenance Manual page 11

(2) Program ROM
This is a 256K/512K/1024K × 16 bits (4/8/16M bit) MASK ROM or FLASH ROM with the
control program for the printer stored. The MPU executes instructions under this program.
The program ROM is assigned to the program memory area of the MPU and is fetched
by the PSEN signal of the MPU.
The following shows the operation of the memory access.
MPU CLOCK
A0~A17/A18/A19
PG-N
PSEN-N
D0~D15
42089201TH Rev.4
MPU
A0~A17/A18/A19
D0~D15
PG-N
CSO
PSEN
Program
IN
ROM
CE
OE
Program
IN
Oki Data CONFIDENTIAL
Program
IN
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