IC89C54 Datasheet, PDF (11/24 Pages) Integrated Circuit Solution Inc – CMOS SINGLE CHIP 8-BIT MICROCONTROLLER with 16/32/64-Kbytes of FLASH

IC89C54/58/64
Timeout
Timeout indicates whether the program or erase time has
exceeded a specified internal timer limit. Under these
conditions Timeout go to high and Ready/BUSY remains a
low. This is a failed condition that indicates the program or
erase cycle was not successful completed. If there are any
program or erase failure in erasing operation, Timeout go to
high and Ready/BUSY remains low.
It is cleared by any rising edge of written signal (like
Program Main Code, Chip Erase, …etc.). The time from
written signal to Timeout=1 is re-initiated at every written
signal’s rising edge. It is high when the program or erase
operations don’t complete and have no newly written signal
in the expected time.
Programming a IC89C54/58/64
To program new data into the memory array, supply 5
volts to VDD and RST, and perform the following steps.
1. Set RST to high and PSEN to low.
2. Raise EA High (either 12V or 5V).
3. Read the “Read Signature Bytes” command to ensure
the correct programming algorithm.
4. Verify that the memory blocks for programming are in
the erased state, FFH. If they are not erased, then
erase
them using the appropriate Erase command.
5. Set P2.6, P2.7, P3.6, P3.7 to a properly programming
combination.
6. Select the memory location using the address lines (P1
[0:7], P2[0:5], P3[2:3]).
7. Present the data in on P0[0:7].
8. Pulse ALE/PROG.
9. Wait for low to high transition on Ready/Busy(P3.4) or
Timeout pin(P3.5). If Ready/Busy is from low to
high, this address is programmed completely. If the
Timeout signal is from low to high before Ready/Busy
goes high, this byte is failed in programming.
10. Repeat steps 6~9 until programming is finished.
Lock bits Features
The IC89C54/58/64 provide three lock bits to protect the embedded program against software piracy. These three
bytes are user programmable. The relation between lock bits status and protection type are listed in table 5.
Table 5. Lock Bits Features
Program Lock bits
LB1 LB2 LB3
1U
UU
2P
UU
3P
4P
PU
PP
Protection Type
No program lock feature enabled.
MOVC instructions executed from external program memory are disabled from fetching
code bytes from internal memory, #EA is sampled and latched on reset, and Data
verification is disabled. (“Verify Signature Byte” and “Verify Lock Bits are still enabled.)
Same as 2, also further written operation of the Flash is disabled
Same as 3, also external execution is disabled
Integrated Circuit Solution Inc.
11
MC009-0B