Technical information

Operating Precautions for CPDW9X/NT-CDR-V85X, Y-GHS-MULTI-V800

Customer Notification r20tu0003ed1812 33

No. a21

Loop optimization on volatile access generates endless loop

Version Information

V3.5.1

Details

Loop optimization on volatile access generates endless loop. The second query on volatile char

CANES0 causes an endless loop.

Example:

test.c:

#define CANC0 *((volatile unsigned char *) (0x03fec121))

#define CANES0 *((volatile unsigned char *) (0x03fec125))

void main (void)

{

CANC0= 0x01; // Disable CAN activity

while ((CANES0 & 0x08)==0); // Wait for INIT bit set

CANC0= 0x00; // Enable CAN activity

while ((CANES0 & 0x08)); // Wait for INIT bit clear

}

Command Sequence

ccv850e -noobj -g -list -passsource -Oloop v030211a.c -o v030211a

Workaround

A new compiler (PATCH to 3.5.1b4), which fixes this problem, can be downloaded from the NEC

WEB page(s) at http://www.renesas.eu/updates?id=443