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CHAPTER 9 WRITING TO AND VERIFYING PROGRAM MEMORY (PROM)
CHAPTER 9 WRITING TO AND VERIFYING PROGRAM MEMORY (PROM)
The program memory in the µPD75P0016 consists of a one-time PROM (16384 x 8 bits).
Writing to and verifying the contents of the one-time PROM is accomplished by using the pins shown in
the table below. Note that address inputs are not used; instead, the address is updated using the clock input
from the X1 pin.
Pin name Function
V
PP
Voltage is applied to this pin when writing to the program memory or verifying its
contents (normally V
DD
electric potential).
X1, X2 Address update clock inputs used when writing to the program memory or verifying
its contents. The X2 pin is used to input the inverted signal of the X1 pin input.
MD0-MD3 Operation mode selection pins used when writing to the program memory or
verifying its contents.
P40 to P43 I/O pins for 8-bit data used when writing to the program memory or verifying
(low-order four bits) its contents.
P50 to P53
(high-order four bits)
V
DD
Power voltage is applied to this pin. During normal operation, 2.2 to 5.5 V should
be applied; +6 V should be applied when writing to the program memory or verifying
its contents.
Cautions 1. The µPD75P0016CU/GB does not have an erasure window, so the erasing with
ultraviolet radiation cannot be performed.
2. Handle the pins not used for writing to or verifying the program memory, as follows:
• Pins other than XT2: Connect these pins to V
SS
through pull-down resistors.
• XT2 pin: Open
*
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