SLAU144K December 2004 – August 2022 MSP430AFE221 , MSP430AFE222 , MSP430AFE223 , MSP430AFE231 , MSP430AFE232 , MSP430AFE233 , MSP430AFE251 , MSP430AFE252 , MSP430AFE253 , MSP430F2001 , MSP430F2002 , MSP430F2003 , MSP430F2011 , MSP430F2012 , MSP430F2013 , MSP430F2101 , MSP430F2111 , MSP430F2112 , MSP430F2121 , MSP430F2122 , MSP430F2131 , MSP430F2132 , MSP430F2132-EP , MSP430F2232 , MSP430F2234 , MSP430F2252 , MSP430F2252-Q1 , MSP430F2254 , MSP430F2272 , MSP430F2272-Q1 , MSP430F2274 , MSP430F2274-EP , MSP430F233 , MSP430F2330 , MSP430F235 , MSP430F2350 , MSP430F2370 , MSP430F2410 , MSP430F2416 , MSP430F2417 , MSP430F2418 , MSP430F2419 , MSP430F247 , MSP430F2471 , MSP430F248 , MSP430F2481 , MSP430F249 , MSP430F2491 , MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619 , MSP430G2001 , MSP430G2101 , MSP430G2102 , MSP430G2111 , MSP430G2112 , MSP430G2121 , MSP430G2131 , MSP430G2132 , MSP430G2152 , MSP430G2153 , MSP430G2201 , MSP430G2201-Q1 , MSP430G2202 , MSP430G2203 , MSP430G2210 , MSP430G2211 , MSP430G2212 , MSP430G2213 , MSP430G2221 , MSP430G2230 , MSP430G2231 , MSP430G2231-Q1 , MSP430G2232 , MSP430G2233 , MSP430G2252 , MSP430G2253 , MSP430G2302 , MSP430G2303 , MSP430G2312 , MSP430G2313 , MSP430G2332 , MSP430G2333 , MSP430G2352 , MSP430G2353 , MSP430G2402 , MSP430G2403 , MSP430G2412 , MSP430G2413 , MSP430G2432 , MSP430G2433 , MSP430G2444 , MSP430G2452 , MSP430G2453 , MSP430G2513 , MSP430G2533 , MSP430G2544 , MSP430G2553 , MSP430G2744 , MSP430G2755 , MSP430G2855 , MSP430G2955 , MSP430TCH5E
CMPA | Compare the 20-bit source with a 20-bit destination register | ||
Syntax |
CMPA Rsrc,Rdst | ||
CMPA #imm20,Rdst | |||
Operation | (.not. src) + 1 + Rdst or Rdst – src | ||
Description | The 20-bit source operand is subtracted from the 20-bit destination CPU register. This is made by adding the 1s complement of the source + 1 to the destination register. The result affects only the status bits. | ||
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 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 20-bit immediate operand and R6 are compared. If they are equal, the program continues at label EQUAL. |
CMPA #12345h,R6 ; Compare R6 with 12345h
JEQ EQUAL ; R5 = 12345h
... ; Not equal
Example | The 20-bit values in R5 and R6 are compared. If R5 is greater than (signed) or equal to R6, the program continues at label GRE. |
CMPA R6,R5 ; Compare R6 with R5 (R5 - R6)
JGE GRE ; R5 >= R6
... ; R5 < R6