87C51RA Ver la hoja de datos (PDF) - Intel

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87C51RA

CHMOS SINGLE-CHIP 8-BIT MICROCONTROLLER

Intel 

8XC51RA RB RC

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

87C51RX the following sequence must be exer-

cised

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 VPP from VCC 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 87C51RX

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

272659 – 20

17

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