SLAU367P October 2012 – April 2020 MSP430FR5041 , MSP430FR5043 , MSP430FR50431 , MSP430FR5847 , MSP430FR58471 , MSP430FR5848 , MSP430FR5849 , MSP430FR5857 , MSP430FR5858 , MSP430FR5859 , MSP430FR5867 , MSP430FR58671 , MSP430FR5868 , MSP430FR5869 , MSP430FR5870 , MSP430FR5872 , MSP430FR58721 , MSP430FR5887 , MSP430FR5888 , MSP430FR5889 , MSP430FR58891 , MSP430FR5922 , MSP430FR59221 , MSP430FR5947 , MSP430FR59471 , MSP430FR5948 , MSP430FR5949 , MSP430FR5957 , MSP430FR5958 , MSP430FR5959 , MSP430FR5962 , MSP430FR5964 , MSP430FR5967 , MSP430FR5968 , MSP430FR5969 , MSP430FR5969-SP , MSP430FR59691 , MSP430FR5970 , MSP430FR5972 , MSP430FR59721 , MSP430FR5986 , MSP430FR5987 , MSP430FR5988 , MSP430FR5989 , MSP430FR5989-EP , MSP430FR59891 , MSP430FR5992 , MSP430FR5994 , MSP430FR59941 , MSP430FR6005 , MSP430FR6007 , MSP430FR6035 , MSP430FR6037 , MSP430FR60371 , MSP430FR6041 , MSP430FR6043 , MSP430FR60431 , MSP430FR6045 , MSP430FR6047 , MSP430FR60471 , MSP430FR6820 , MSP430FR6822 , MSP430FR68221 , MSP430FR6870 , MSP430FR6872 , MSP430FR68721 , MSP430FR6877 , MSP430FR6879 , MSP430FR68791 , MSP430FR6887 , MSP430FR6888 , MSP430FR6889 , MSP430FR68891 , MSP430FR6920 , MSP430FR6922 , MSP430FR69221 , MSP430FR6927 , MSP430FR69271 , MSP430FR6928 , MSP430FR6970 , MSP430FR6972 , MSP430FR69721 , MSP430FR6977 , MSP430FR6979 , MSP430FR69791 , MSP430FR6987 , MSP430FR6988 , MSP430FR6989 , MSP430FR69891
| SUBC[.W] | Subtract source word with carry from destination word | ||
| SUBC.B | Subtract source byte with carry from destination byte | ||
| Syntax | SUBC src,dst or SUBC.W src,dst | ||
| SUBC.B src,dst | |||
| Operation | (.not.src) + C + dst → dst or dst – (src – 1) + C → dst | ||
| Description | The source operand is subtracted from the destination operand. This is done by adding the 1s complement of the source + carry to the destination. The source operand is not affected, the result is written to the destination operand. Used for 32, 48, and 64-bit operands. | ||
| Status Bits | N: | Set if result is negative (MSB = 1), reset if positive (MSB = 0) | |
| Z: | Set if result is zero, reset otherwise | ||
| C: | Set if there is a carry from the MSB, reset otherwise | ||
| V: | Set if the subtraction of a negative source operand from a positive destination operand delivers a negative result, or if the subtraction of a positive source operand from a negative destination operand delivers a positive result, reset otherwise (no overflow) | ||
| Mode Bits | OSCOFF, CPUOFF, and GIE are not affected. | ||
| Example | A 16-bit constant 7654h is subtracted from R5 with the carry from the previous instruction. R5.19:16 = 0 | ||
SUBC.W #7654h,R5 ; Subtract 7654h + C from R5
| Example | A 48-bit number (3 words) pointed to by R5 (20-bit address) is subtracted from a 48-bit counter in RAM, pointed to by R7. R5 points to the next 48-bit number afterwards. The address R7 points to is in full memory range. | ||
SUB @R5+,0(R7) ; Subtract LSBs. R5 + 2
SUBC @R5+,2(R7) ; Subtract MIDs with C. R5 + 2
SUBC @R5+,4(R7) ; Subtract MSBs with C. R5 + 2
| Example | Byte CNT is subtracted from the byte, R12 points to. The carry of the previous instruction is used. The address of CNT is in lower 64 K. | ||
SUBC.B &CNT,0(R12) ; Subtract byte CNT from @R12