UPD75P216ACW NEC, UPD75P216ACW Datasheet - Page 12

• Manufacturer Part Number: UPD75P216ACW
• Description: 4-BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

3.3 PROM READ PROCEDURE
figure)
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10) Return the V
(11) Turn off the power.
12
P40-P43
P50-P53
V
The PROM contents can be read in the verify mode by using the following procedure: (see the following
V
DD
V
PP
MD0
(P30)
MD1
(P31)
MD2
(P32)
MD3
(P33)
DD
Pull unused pins to V
Supply 5 volts to the V
Wait for 10 s.
Select the zero clear program memory address mode.
Supply 6 volts to the V
Select the program inhibit mode.
Select the verify mode. Apply four pulses to the X1 pin. Every four clock pulses will output the data
stored in one address.
Select the program inhibit mode.
Select the zero clear program memory address mode.
V
V
V
+1
X1
DD
DD
PP
DD
and V
PP
SS
DD
DD
pins back to + 5 volts.
through resistors. Set the X1 pin low.
”L“
and V
and 12.5 volts to the V
Fig. 3-2
PP
pins.
Output data
Timing of Program Memory Read
PP
pins.
Output data
PD75P216A