tmp88cs34ng TOSHIBA Semiconductor CORPORATION, tmp88cs34ng Datasheet - Page 40

• Manufacturer Part Number: tmp88cs34ng
• Description: Cmos 8-bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Note: Corrective address must be assigned to 1st byte of instruction codes on the program jump
(2) Data replacement mode
area with the new instead of correcting the data reference instruction when that reference
data is changed.
However, when this mode is used, if there is a need to replace only the fixed data in ROM,
the instruction to reference this ROM data should be corrected. Thus, a large amount of
ROM is required for the patch program. To avoid this, the system has the data replacement
mode. With this mode, three consecutive bytes of data can be replaced for each bank. (For
an instruction which accesses only one byte, only the first byte can be replaced. For an
instruction which accesses only two bytes, the two consecutive bytes can be replaced.)
Setting ROMCCR CMx (x: 0 to 3) to “1” puts the system in the data replacement mode.
Specify the start address of ROM data to be replaced as the corrective ROM address. Then,
specify the new three-byte data as the patch data.
Note: For data replacement mode, the corrective address should be the address of fixed data
In the data replacement mode, the system replaces reference data stored in the ROM
The program jump mode reduces the complexity of correcting the processing routine.
Example 1: Setting the Program Correction Circuit with the Initial Routine
mode.
program correction circuit's register as follows.
1.
2.
3.
4.
5.
6.
Using the initial routine program, which is executed right after reset, set the
(including a vector). (The operation code and operand cannot be changed.)
0C020H
0C086H
Read the flag, which indicates whether to use the program correction circuit, from
the external memory.
If that circuit is not used, perform normal initial processing.
If it is used, set CMx to “1” to establish the data replacement mode.
Read the address of the data to be replaced and the patch data from the external
memory.
Set the address and patch data, which were read in step 4., in ROMCDR.
Repeat steps 4. and 5. as many times as there are required banks.
006BFH
00FFFH
0C085H
FFFFFH
00000H
0003FH
00040H
00F80H
04000H
Bug area
ROM
RAM
DBR
SFR
88CS34-40
JP 0C086H
program
Return
Patch
004EFH
004F0H
00400H
TMP88CS34/CP34
2007-09-12