Description:

Pop the top short on the stack and write it to the memory-mapped IO port specified by the address parameter.

Data (2 bytes):

address: address value that is the memory location where the short popped from the stack is to be stored.

Pseudo Code:

port[program[pc + 1] : program[pc + 2]] = (short) stack[sp - 2]
sp = sp - 2
pc = pc + 3

Flags Affected:

D	H	C	Z	N

Possible Errors:

tvmStackUnderflow	-	There is no short on the stack to pop.
tvmStackIOErr	-	The write operation to the memory-mapped IO port is invalid.

Example:

popsm

Before stack   top 1 0x0B 2 0x17 3 0xAA 4 0x32 5 0x02   bottom

After stack   top 1 0xAA 2 0x32 3 0x02   bottom