Sbc [%ir],0,n4, Sbc [%ir]+,0,n4 – Epson S1C63000 User Manual
Page 136
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EPSON
S1C63000 CORE CPU MANUAL
CHAPTER 4: INSTRUCTION SET
SBC [%ir],0,n4
Subtract carry from location [ir reg.] in specified radix
2 cycles
Function:
[ir]
←
N’s adjust ([ir] - 0 - C)
Subtracts the carry (C) from the data memory addressed by the ir register (X or Y). The opera-
tion result is adjusted with n4 as the radix. The C flag is set according to the radix. This instruc-
tion is useful for borrow processing of n based counters.
Code:
Mnemonic
MSB
LSB
SBC [%X],0,n4
1
1
1
0
0
0
0
0
0 n3 n2 n1 n0 1C00H–1C0FH
SBC [%Y],0,n4
1
1
1
0
0
0
0
1
0 n3 n2 n1 n0 1C20H–1C2FH
Flags:
E
I
C
Z
↓
–
↕
↕
Mode:
Src: Register direct
Dst: Register indirect
Extended addressing: Valid
Extended
LDB %EXT,imm8
operation:
SBC [%X],0,n4
[00imm8]
←
N’s adjust ([00imm8] - 0 - C) (00imm8 = 0000H + 00H to FFH)
LDB %EXT,imm8
SBC [%Y],0,n4
[FFimm8]
←
N’s adjust ([FFimm8] - 0 - C) (FFimm8 = FF00H + 00H to FFH)
Note:
n4 should be specified with a value from 1 to 16. When 16 is specified for n4, the low-order 4
bits of the machine code (n3–n0) become 0000B.
SBC [%ir]+,0,n4
Subtract carry from location [ir reg.] in specified radix and increment ir reg. 2 cycles
Function:
[ir]
←
N’s adjust ([ir] - 0 - C), ir
←
ir + 1
Subtracts the carry (C) from the data memory addressed by the ir register (X or Y). The opera-
tion result is adjusted with n4 as the radix. Then increments the ir register (X or Y). The flags
change due to the operation result of the data memory and the increment result of the ir
register does not affect the flags. The C flag is set according to the radix. This instruction is
useful for borrow processing of n based counters.
Code:
Mnemonic
MSB
LSB
SBC [%X]+,0,n4
1
1
1
0
0
0
0
0
1 n3 n2 n1 n0 1C10H–1C1FH
SBC [%Y]+,0,n4
1
1
1
0
0
0
0
1
1 n3 n2 n1 n0 1C30H–1C3FH
Flags:
E
I
C
Z
↓
–
↕
↕
Mode:
Src: Register direct
Dst: Register indirect
Extended addressing: Invalid
Note:
n4 should be specified with a value from 1 to 16. When 16 is specified for n4, the low-order 4
bits of the machine code (n3–n0) become 0000B.