Texas Instruments UCD3138 Technical Reference Manual page 460

Dual-State Interworking
Example-1. Code Compiled for 16-BIS State: Sum( )
• C Program
int total = 0;
sum(int val1, int val2)
{
int val = max(val1, val2);
total += val;
}
• 16-bit assembly program
;*****************************************************************
; function venner: _sum
;*****************************************************************
_sum:
.state32
STMFD sp!, {lr}
ADD lr, pc, #1
BX lr
.state16
BL $sum
BX pc
NOP
.state16
.sect ".text"
.global $sum
;*****************************************************************
; function def: $sum
;*****************************************************************
$sum:
PUSH {LR}
BL $max
LDR A2, CON1
LDR A3, [A2, #0]
ADD A1, A1, A3
STR A1, [A2, #0]
POP {PC}
;*****************************************************************
; constant table
;*****************************************************************
sect ".text"
.align4
460
ARM7TDMI-S MPUSS
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SNIU028A – February 2016 – Revised April 2016
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