IS89C51 Datasheet, PDF (38/48 Pages) Integrated Silicon Solution, Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER with 4-Kbytes of FLASH

IS89C51
ISSI ^®
Programming Algorithm
Before programming the IS89C51, the control signals, the
address, data should be setup according to the
programming mode table and programming interface. To
program the IS89C51, the following sequence should be
followed:
1. Insert the desired memory location on the
address bus.
2. Insert the appropriate data byte on the data bus.
3. Active the correct combination of control signals.
4. Raise EA / VPP to 12V.
5. Pulse ALE / PROG once to program a byte in the
Flash array, Encryption array or the lock bits.
6. Set EA / VPP to 5 V and verify data. If the data is correct
then execute step 7, otherwise execute steps 1-6.
7. Repeat steps 1 through 6, changing the address
and data for the entire array or until the end of the
object file is reached.
Program Verify
If lock bits LB1, LB2 and LB3 have not been programmed,
the programmed code data can be read back via the
address and data lines for verification. The lock bits cannot
be verified directly. Verification of lock bits is achieved by
observing that their features are enabled.
To verify the data after all addresses are programmed
completely, power down the IS89C51 and then reapply
power. The programmed data can then be verified by
applying the verify signals to the device.
Erasing Chip
All Flash memory cells must be programmed to '00' (include
encryption array and lock bits) before the chip is erased.
The entire Flash array is erased electrically by using the
proper combination of control signals and by holding ALE/
PROG low for tGLGHE duration (See Table 14. Flash
Programming and Verification Characteristics for tGLGHE
value.) After the chip is erased, the code array and lock bits
are written with all “1”s. If any Flash memory cell is not '1'
(including lock bits), repeat the chip erase again. The chip
erase operation must be executed successfully before the
code memory can be re-programmed.
Reading the Signature Bytes
The signature bytes are read by the same procedure as a
normal verification of locations 030H, 031H and 032H,
except that P3.6 and P3.7 need to be pulled to a logic low.
The values returned are:
Signature
Location
(030H)
(031H)
(032H)
Value
D5H indicates manufactured
by ISSI
52H indicates IS89C51
FFH indicates programming
voltage is 12V
38
1-800-379-4774 — Integrated Silicon Solution, Inc.
MC016-1C
11/21/98