138 EPSON S1C63000 CORE CPU MANUAL
CHAPTER 4: INSTRUCTION SET
SUB [%ir],imm4 Subtract immediate data imm4 from location [ir reg.] 2 cycles
Function: [ir] ← [ir] - imm4
Subtracts the 4-bit immediate data imm4 from the data memory addressed by the ir register (X
or Y).
Code:
Mnemonic MSB LSB
SUB [%X],imm4 110000000i3i2i1i01800H–180FH
SUB [%Y],imm4 110000010i3i2i1i01820H–182FH
Flags: EICZ
↓ – ↕↕
Mode: Src: Immediate data
Dst: Register indirect
Extended addressing: Valid
Extended LDB %EXT,imm8
operation: SUB [%X],imm4 [00imm8] ← [00imm8] - imm4 (00imm8 = 0000H + 00H to FFH)
LDB %EXT,imm8
SUB [%Y],imm4 [FFimm8] ← [FFimm8] - imm4 (FFimm8 = FF00H + 00H to FFH)
SUB [%ir]+,imm4
Subtract immediate data imm4 from location [ir reg.] and increment ir reg. 2 cycles
Function: [ir] ← [ir] - imm4, ir ← ir + 1
Subtracts the 4-bit immediate data imm4 from the data memory addressed by the ir register (X
or Y). 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.
Code:
Mnemonic MSB LSB
SUB [%X]+,imm4 110000001i3i2i1i01810H–181FH
SUB [%Y]+,imm4 110000011i3i2i1i01830H–183FH
Flags: EICZ
↓ – ↕↕
Mode: Src: Immediate data
Dst: Register indirect
Extended addressing: Invalid
