Datasheet

Instruction Set Description

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4.6.2.9 CALL

CALL Call a subroutine in lower 64KB

CALL dst

Syntax

Operation dst → PC 16-bit dst is evaluated and stored

SP – 2 → SP

PC → @SP updated PC with return address to TOS

tmp → PC saved 16-bit dst to PC

Description A subroutine call is made from an address in the lower 64KB to a subroutine address in

the lower 64KB. All seven source addressing modes can be used. The call instruction is

a word instruction. The return is made with the RET instruction.

Status Bits Status bits are not affected.

PC.19:16 cleared (address in lower 64KB)

Mode Bits OSCOFF, CPUOFF, and GIE are not affected.

Examples Examples for all addressing modes are given.

Immediate Mode: Call a subroutine at label EXEC (lower 64KB) or call directly to

address.

CALL #EXEC ; Start address EXEC

CALL #0AA04h ; Start address 0AA04h

Symbolic Mode: Call a subroutine at the 16-bit address contained in address EXEC.

EXEC is located at the address (PC + X) where X is within PC + 32 K.

CALL EXEC ; Start address at @EXEC. z16(PC)

Absolute Mode: Call a subroutine at the 16-bit address contained in absolute address

EXEC in the lower 64KB.

CALL &EXEC ; Start address at @EXEC

CALL R5 ; Start address at R5

Indirect Mode: Call a subroutine at the 16-bit address contained in the word pointed to by

CALL @R5 ; Start address at @R5

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CPUX SLAU144J–December 2004–Revised July 2013

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