TMP88CS38 datasheet(35/226 Pages) TOSHIBA

35 / 226 page

TMP88CS38/CM38A/CP38A

2007-09-12

88CS38-35

1.7

ROM Corrective Function

The ROM corrective function can patch the part (s) of on-chip ROM with some bugs.

The ROM corrective function have two modes. One is to replaced the instruction on a certain

address in the ROM with the jump instruction to branch into the RAM area where the patched

codes (Program jump mode). The other is to replace a byte or a word (2 or 3 bytes) length data in

the ROM with the patched data (Data replacement mode). Four independent location can be

patched.

Note 1: When use ROM corrective circuit, it is necessary to contain a program which operates to load

patched program and/or replacement data from external memory into an internal data RAM

in an initial routine.

Note 2: The address of a instruction for IDLE mode can not be specificated as start address of

corrective area.

Note 3: The BM88CS38N0A does not support the ROM corrective circuit. Use the TMP88PS38 to

debug a program of this circuit. In this case, note the following.

In program jump mode, jump target addresses that can be specified with the

TMP88CM38A/CP38A (002C0H to 006BFH) are different from those that can be specified

with the TMP88PS38 (002C0H to 008BFH). Therefore, if a jump target address is within a

range of 006C0H to 008BFH, it is necessary to change this addresse and also addresses for

loading a patch program.

Example:

ROM corrective circuit

ROMCDR

Serial

bus

interface

RAM

• Correction mode

• Correction code

• Patch program

TMP88CS38 Datasheet(PDF) 35 Page - Toshiba Semiconductor