INSTRUCTION SET
S3C80A5B
6-68
PUSHUI
—
Push User Stack (Incrementing)
PUSHUI
dst,src
Operation:
IR
←
IR + 1
dst
←
src
This instruction is used for user-defined stacks in the register file. PUSHUI increments the user
stack pointer and then loads the contents of the source into the register location addressed by the
incremented user stack pointer.
Flags:
No flags are affected.
Format:
Bytes
Cycles
Opcode
(Hex)
Addr Mode
dst src
opc
dst
src
3
8
83
IR
R
Example:
Given: Register 00H = 03H, register 01H = 05H, and register 04H = 2AH:
PUSHUI @00H,01H
→
Register 00H = 04H, register 01H = 05H, register 04H = 05H
If the user stack pointer (register 00H, for example) contains the value 03H, the statement
"PUSHUI @00H,01H" increments the user stack pointer by one, leaving the value 04H. The 01H
register value, 05H, is then loaded into the location addressed by the incremented user stack
pointer.