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
| * RETA | Return from subroutine | ||
| Syntax | RETA | ||
| Operation | @SP → PC.15:0 LSBs (15:0) of saved PC to PC.15:0 | ||
| SP + 2 → SP | |||
| @SP → PC.19:16 MSBs (19:16) of saved PC to PC.19:16 | |||
| SP + 2 → SP | |||
| Emulation | MOVA @SP+,PC | ||
| Description | The 20-bit return address information, pushed onto the stack by a CALLA instruction, is restored to the PC. The program continues at the address following the subroutine call. The SR bits SR.11:0 are not affected. This allows the transfer of information with these bits. | ||
| Status Bits | N: | Not affected | |
| Z: | Not affected | ||
| C: | Not affected | ||
| V: | Not affected | ||
| Mode Bits | OSCOFF, CPUOFF, and GIE are not affected. | ||
| Example | Call a subroutine SUBR from anywhere in the 20-bit address space and return to the address after the CALLA | ||
CALLA #SUBR ; Call subroutine starting at SUBR
... ; Return by RETA to here
SUBR PUSHM.A #2,R14 ; Save R14 and R13 (20 bit data)
... ; Subroutine code
POPM.A #2,R14 ; Restore R13 and R14 (20 bit data)
RETA ; Return (to full address space)