Dear Will-san,
Today I borrowed a PSoC-5LP board from my colleague and ran tests using following main.c
==============================
#include "project.h"
#include <stdio.h>
char str[128] ; /* print buffer */
uint32_t count = 0 ;
// register uint32_t count asm("r6") ;
void init_hardware(void)
{
CyGlobalIntEnable; /* Enable global interrupts. */
UART_Start() ;
}
void UART_UartPutString(char *str)
{
while(str && *str) {
UART_PutChar(*str++) ;
}
}
int main(void)
{
uint32_t loop = 0 ;
volatile int flag = 0 ;
init_hardware() ;
sprintf(str, "DWT test program (%s %s)\r\n", __DATE__, __TIME__) ;
UART_UartPutString(str) ;
for(;;) {
if ((count % 0x10000) == 0) {
sprintf(str, "Loop %d\r\n", loop++ ) ;
UART_UartPutString(str) ;
count = 0 ;
flag = 0 ;
}
count++ ;
#if 0
if (count == 0x100) {
flag = 1 ;
}
#endif
}
}
==============================
(1) count is a usual global variable and #if is 0 at the end part of the main.
set Condition Break "count == 0x100" at the line of "count++"
It took about 63sec to hit the first break.
(2) count is a register variable and #if is 0 at the end part of the main.
set Condition Break "count == 0x100" at the line of "count++"
it took about 52sec to hit the first break.
(3) count is a usual global variable and #if if 1 at the end part of the main.
set Break at the line of "flag = 1"
it took less than a second to hit the first break.
So my current conclusion(s) are
1. Yes, using register variable makes the test faster but not quite.
2. Although modification to the source is required,
placing a trap routine makes the "cost" of time much smaller.
moto
