Search

What are you looking for?

CALL

June 23, 20191 min read

Call Subroutine

Call Subroutine. First, return address (PC+1) is pushed onto the stack. The eleven-bit immediate address is loaded into PC bits <10:0>. The upper bits of the PC are loaded from PCLATH. CALL is a two-cycle instruction.

[the_ad id="3059"]

Syntax:

[ label ] CALL k

Operation:

(PC)+ 1→ TOS,
k → PC<10:0>,
(PCLATH<4:3>) → PC<12:11>

Operands:

  •  k is from 0 to 2047 (decimal)

Status Affected: None

Example:

CALL SUB1

Note: SUB1 must have a RETURN statement to pop-out the PC of the caller from the stack.

[the_ad id="3059"]

Roland Pelayo started TMM in 2015. He is a firmware engineer who has over ten years of experience in developing electronic and microcontroller-based systems. Roland's designs include medical devices, security and automation, robots, emergency alert systems, and educational training modules.   Have something that you like Roland to write about here? or do you need consultation for microcontroller firmware projects? just contact him via the contact page.