M37212 Mitsubishi, M37212 Datasheet - Page 51

• Manufacturer Part Number: M37212
• Description: SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
• Manufacturer: Mitsubishi

8.9 ROM CORRECTION FUNCTION
This can correct program data in ROM. Up to 2 addresses can be
corrected, a program for correction is stored in the ROM correction
memory in RAM as the top address. The ROM correction vectors are
2 vectors.
Set the address of the ROM data to be corrected into the ROM cor-
rection address register. When the value of the counter matches the
ROM data address in the ROM correction vector as the top address,
the main program branches to the correction program stored in the
ROM memory for correction. To return from the correction program
to the main program, the op code and operand of the JMP instruction
(total of 3 bytes) are necessary at the end of the correction program.
The ROM correction function is controlled by the ROM correction
enable register.
Notes 1: Specify the first address (op code address) of each instruction as the
Fig. 8.9.2 ROM Correction Enable Register
Rev. 1.0
2: Use the JMP instruction (total of 3 bytes) to return from the correction
3: Do not set the same ROM correction address to vectors 1 and 2.
4: Only M37212M8-XXXSP and M37212EFSP/FP have ROM correc-
Vector 1 : address 02C0
Vector 2 : address 02E0
ROM correction address.
program to the main program.
tion function.
R O M C o r r e c t i o n E n a b l e R e g i s t e r
b 7 b 6 b 5 b 4 b 3 b 2 b 1 b 0
0
16
16
0
2 , 3 F i x t h e s e b i t s t o “ 0 . ”
M37212M4/M8–XXXSP, M37212M6–XXXSP/FP
t o
B
0
1
4
7
R O M c o r r e c t i o n e n a b l e r e g i s t e r ( R C R ) [ A d d r e s s 0 2 1 B
N o t h i n g i s a s s i g n e d . T h e s e b i t s a r e w r i t e d i s a b l e b i t s . W h e n
t h e s e b i t s a r e r e a d o u t , t h e v a l u e s a r e “ 0 . ”
V e c t o r 1 e n a b l e b i t ( R C 0 )
V e c t o r 2 e n a b l e b i t ( R C 1 )
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER for VOLTAGE SYNTHESIZER
N a m e
Fig. 8.9.1 ROM Correction Address Registers
0 : D i s a b l e d
1 : E n a b l e d
0 : D i s a b l e d
1 : E n a b l e d
R O M c o r r e c t i o n a d d r e s s 1 ( h i g h - o r d e r )
R O M c o r r e c t i o n a d d r e s s 1 ( l o w - o r d e r )
R O M c o r r e c t i o n a d d r e s s 2 ( h i g h - o r d e r )
R O M c o r r e c t i o n a d d r e s s 2 ( l o w - o r d e r )
F u n c t i o n s
with ON-SCREEN DISPLAY CONTROLLER
MITSUBISHI MICROCOMPUTERS
1 6
A f t e r r e s e t
M37212EFSP/FP
]
0
0
0
0
R W
R W
R W
R W
R —
0 2 1 7
0 2 1 8
0 2 1 9
0 2 1 A
1 6
1 6
1 6
1 6
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