MSP430 Instructions
4-107
16-Bit MSP430X CPU
SUB[.W]
Subtract source word from destination word
SUB.B
Subtract source byte from destination byte
Syntax
SUB
src,dst or SUB.W src,dst
SUB.B
src,dst
Operation
(.not.src) + 1 + dst
→
dst
or dst − src
→
dst
Description
The source operand is subtracted from the destination operand. This is made
by adding the 1’s complement of the 1 to the destination. The source
operand is not affected, the result is written to the destination operand.
Status Bits
N:
Set if result is negative (src > dst), reset if positive (src <= dst)
Z:
Set if result is zero (src = dst), reset otherwise (src
≠
dst)
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 des-
tination operand delivers a negative result, or if the subtraction of a posi-
tive 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 RAM word EDE.
SUB
#7654h,&EDE ; Subtract 7654h from EDE
Example
A table word pointed to by R5 (20-bit address) is subtracted from R7.
Afterwards, if R7 contains zero, jump to label TONI. R5 is then
auto-incremented by 2. R7.19:16 = 0.
SUB
@R5+,R7
; Subtract table number from R7. R5 + 2
JZ
TONI
; R7 = @R5 (before subtraction)
...
; R7 <> @R5 (before subtraction)
Example
Byte CNT is subtracted from byte R12 points to. The address of CNT is within
PC
±
32 K. The address R12 points to is in full memory range.
SUB.B
CNT,0(R12)
; Subtract CNT from @R12
Содержание MSP430x4xx Family
Страница 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Страница 2: ......
Страница 6: ...vi ...
Страница 114: ...3 76 RISC 16 Bit CPU ...
Страница 304: ...5 20 FLL Clock Module ...
Страница 340: ...7 8 Supply Voltage Supervisor ...
Страница 348: ...8 8 16 Bit Hardware Multiplier ...
Страница 372: ...9 24 32 Bit Hardware Multiplier ...
Страница 400: ...10 28 DMA Controller ...
Страница 428: ...13 10 Basic Timer1 ...
Страница 466: ...15 24 Timer_A ...
Страница 522: ...17 30 USART Peripheral Interface UART Mode ...
Страница 544: ...18 22 USART Peripheral Interface SPI Mode ...
Страница 672: ...23 12 Comparator_A ...
Страница 692: ...24 20 LCD Controller ...
Страница 746: ...26 28 ADC12 ...