80C52 Datasheet, PDF (20/23 Pages) Intel Corporation – CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER

8XC52 54 58
See Table 4 for proper input on these pins
Figure 10 Programming the EPROM
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PROGRAMMING ALGORITHM
Refer to Table 4 and Figures 10 and 11 for address
data and control signals set up To program the
87C5X the following sequence must be exercised
1 Input the valid address on the address lines
2 Input the appropriate data byte on the data
lines
3 Activate the correct combination of control sig-
nals
4 Raise EA V_PP from V_CC to 12 75V g0 25V
5 Pulse ALE PROG 5 times for the EPROM ar-
ray and 25 times for the encryption table and
the lock bits
Repeat 1 through 5 changing the address and data
for the entire array or until the end of the object file is
reached
PROGRAM VERIFY
Program verify may be done after each byte or block
of bytes is programmed In either case a complete
verify of the programmed array will ensure reliable
programming of the 87C5X
The lock bits cannot be directly verified Verification
of the lock bits is done by observing that their fea-
tures are enabled
Figure 11 Programming Signal’s Waveforms
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