Maxim Integrated DS4830A Optical Microcontroller - Manual (Page 219)

DS4830A User’s Guide
219
PUSH src Push Word to the Stack
Description:
Increments 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
0040h  SP (after PUSH #40h)
0F3Fh  SP (after PUSH GR)
xxxxh  SP (initial)
xxxxh
RET Return from Subroutine
Description:
RET pops a single word from the stack (@SP) into the Instruction Pointer (IP) and
decrements the stack pointer (SP). The decremented 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
0103h  SP (before RET)
xxxxh  SP (after RET)
xxxxh