Maxim Integrated MAXQ610 - Manual (Page 183)

14-16
MAXQ610 User’s Guide
PUSH src Push Word to the Stack
Description: Increases the stack depth (decments the stack pointer SP) and pushes a single word specified by
src to the stack (@SP) .
Status Flags: None
Operation:
SP ← ++SP
Encoding: 15 0
f000 1101 ssss ssss
Example(s): PUSH GR ; GR=0F3Fh
PUSH #40h
Stack Data:
xxxxh
xxxxh
← SP (initial)
0F3Fh ← SP (after PUSH GR)
0040h ← SP (after PUSH #40h)
xxxxh
RET Return from Subroutine
Description: RET pops a single word from the stack (@SP) into the Instruction Pointer (IP) and decreases the stack
depth (increments the stack pointer SP) . The modified SP is saved as the new stack pointer (SP) .
Status Flags: None
Operation:
IP ← @SP--
Encoding: 15 0
1000 1100 0000 1101
Example(s): RET
Code Execution:
Addr (IP) Opcode
0311h …
0312h RET
→
0103h …
Stack Data:
xxxxh
xxxxh
← SP (after RET)
0103h ← SP (before RET)
xxxxh
xxxxh