User guide

DS4830A User’s Guide
220
RET C / RET NC Conditional Return on Status Flag
RET Z / RET NZ
RET S
Description: Performs conditional return (RET) based upon the state of a specific processor status flag.
RET C returns if the Carry flag is set while RET NC returns if the Carry flag is clear. RET Z
returns if the Zero flag is set while RET NZ returns if the Zero flag is clear. RET S returns if
the Sign flag is set. See RET for additional information on the return operation.
Status Flags: None
RET C
Operation: C=1: IP  @SP--
C=0: IP  IP + 1
Encoding: 15 0
1010
1100
0000
1101
Example(s): RET C ; C=1, return (RET) is performed.
RET NC
Operation: C=0: IP  @SP--
C=1: IP  IP +1
Encoding: 15 0
1110
1100
0000
1101
Example(s): RET NC ; C=1, return (RET) does not occur
RET Z
Operation: Z=1: IP  @SP--
Z=0: IP  IP + 1
Encoding: 15 0
1001
1100
0000
1101
Example(s): RET Z ; Z=0, return (RET) does not occur
RET NZ
Operation: Z=0: IP  @SP--
Z=1: IP  IP + 1
Encoding: 15 0
1101
1100
0000
1101
Example(s): RET NZ ; Z=0, return (RET) is performed
RET S
Operation: S=1: IP  @SP--
S=0: IP  IP + 1
Encoding: 15 0
1100
1100
0000
1101
Example(s): RET S ; S=0, return (RET) does not occur