1. ACALL
ACALL addr11
Function: Absolute Call
Description: ACALL unconditionally calls a subroutine located at the indicated address. The instruction increments the PC twice to obtain the address of the following instruction, then pushes the 16-bit result onto the stack (low-order byte first) and increments the Stack Pointer twice. The destination address is obtained by successively concatenating the five high-order bits of the incremented PC, opcode bits 7 through 5, and the second byte of the instruction. The subroutine called must therefore start within the same 2 K block of the program memory as the first byte of the instruction following ACALL. No flags are affected.
Example: Initially SP equals 07H. The label SUBRTN is at program memory location 0345 H. After executing the following instruction,
ACALL SUBRTN
at location 0123H, SP contains 09H, internal RAM locations 08H and 09H will contain 25H and 01H, respectively, and the PC contains 0345H.
Bytes: 2
Cycles: 2