Echelon Neuron - Manual (Page 119)

PUSHPOP (Pop from Return Stack and Push onto
Data Stack)
The PUSHPOP instruction pops the byte from the top of the return stack and
pushes it into TOS on the data stack. The PUSHPOP instruction uses the
implicit addressing mode.
You can also use the PUSH [RSP] instruction to save the value at the top of the
return stack without removing it.
See POPPUSH (Pop from Data Stack and Push onto Return Stack) for the
inverse operation.
The PUSHPOP instruction applies to Series 3100, 5000, and 6000 devices.
Syntax:
The PUSHPOP instruction requires no operands:
PUSHPOP
Table 43 describes the attributes of the PUSHPOP instruction.
Table 43. PUSHPOP Instruction
Instruction Hexadecimal
Opcode
Instruction
Size (Bytes)
CPU Cycles
Required
Affect on
Carry Flag
PUSHPOP A7 1 5 None
Example:
The following example uses the POPPUSH instruction to save the contents of
the top of the stack so that it can store other values onto the stack below the top
values. It then uses the PUSHPOP instruction to restore the values to the top
of the stack. The comments show the contents of the data stack and the return
stack for each operation.
poppush ; (A--) R(B--)
poppush ; (--) R(A, B--)
pushd [C] ; (A --) R(A, B --)
pushd [D] ; (D, C --) R(A, B --)
pushd [E] ; (E, D, C --) R(A, B --)
pushpop ; (A, E, D, C -- ) R( B -- )
pushpop ; (B, A, E, D, C -- ) R( -- )
Neuron Assembly Language Reference 109