UPD78P324 Datasheet, PDF (17/80 Pages) NEC – 16-/8-Bit Single-Chip Microcomputers

µPD78P324, 78P324(A)
3. PROM PROGRAMMING
The µPD78P324 incorporates an electrically writable 32768-by-8-bit program PROM and an 8192-by-6-bit
ECC (error correcting code) PROM.
ECC corrects the errors in codes written in the program PROM, thus improving the reliability of the PROM
content. Figure 3-1 shows the memory map in programming mode.
Figure 3-1. Memory Map in Programming Mode
A004H
A003H
A000H
9FFFH
8000H
7FFFH
ECC (for ECW)
ECW
(4 x 8)
PROM for ECC^Note
(8192 x 6)
Program PROM
(32768 x 8)
0000H
Note On the ECC PROM, the lower 6 bits are valid.
When programming, set the RESET pin and the AVDD pin to PROM programming mode. The programming
characteristics of the µPD78P324 are compatible with the µPD27C1001A. However, the programming mode
is compatible only with the byte program mode of the µPD27C1001A. For setting on the PROM programmer,
please select the byte program mode of the 27C1001A mode.
When using the ECC circuit, reset the lowest bit (A000.0) of the lowest byte of the ECW (ECC control word)
to enable the operation of the ECC circuit. ECW is a 4-byte register which controls the operation of the ECC
circuit. ECC and ECW are generated automatically with the ECCGEN (ECC generator) which comes with the
RA78K3 assembler package. (ECC is generated in the lower 6 bits; and the upper 2 bits are fixed to 1.)
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