3. Instruction Set
API
Mnemonic Operands Function
SS2
SX2
01 CALL P
Call Subroutine
OP Valid Range Program Steps
P0~P255
CALL, CALLP: 3 steps
SS2
SX2
SS2
SX2
SS2
SX2
Operands:
S: The destination pointer P of the call subroutine.
Explanations:
1. When the CALL instruction is active it forces the program to run the subroutine associated with
the called pointer.
2. A CALL instruction must be used in conjunction with FEND (API 06) and SRET (API 02)
instructions.
3. The program jumps to the subroutine pointer (located after an FEND instruction) and
processes the contents until an SRET instruction is encountered. This forces the program
flow back to the line of ladder immediately following the original CALL instruction.
Points to note:
1. Subroutines must be placed after FEND instruction.
2. Subroutines must end with SRET instruction.
3. CALL pointers and CJ instruction pointers are not allowed to coincide.
4. CALL instructions can call the same CALL subroutine any number of times.
5. Subroutines can be nested 5 levels including the initial CALL instruction. (If entering the six
levels, the subroutine won’t be executed.)