C6678 FAUCR not showing DIV0 set in test program

Ng Teck

Prodigy 40 points

Hi,

I am writing a test program for C6678, the test program checks for DIV0 below:

extern __cregister volatile unsigned int FAUCR;

void testDIV0(void)

{

double a = 1, b = 1, c = 0;

c = 0;

b = 1 / c;

printf("\nFAUCR = 0x%x", FAUCR);

}

I expect to see DIV0 in FAUCR set, but the output I get is:

FAUCR = 0x800000

Why is FAUCR not showing DIV0? How do I perform tests to enable FAUCR to flag out the exceptions such as

underflow or overflow, the rounding mode, NaNs, denormalized numbers, and inexact results?

Thanks!

over 11 years ago

0 George Mock over 11 years ago

TI__Guru**** 250180 points

What build options did you use? What is the compiler version?

Thanks and regards,

-George

0 Ng Teck over 11 years ago in reply to George Mock

Prodigy 40 points

Hi George,

I am using CCS version 5.5.0.00077, compiler TI V7.4.4, debug (active ) configuration and the flags set are:

-mv6600 --abi=eabi -g --include_path ="C:/ti/ccsv5/tools/compilier/c6000_7.4.4/include"

--include_path ="C:/ti/pdk_C6678_1_1_2_6/packages/ti/drv/qmss"

--include_path ="C:/ti/pdk_C6678_1_1_2_6/packages/ti/drv/cppi"

--include_path ="C:/ti/pdk_C6678_1_1_2_6/packages/ti/csl" --display_error_number

--diag_warning=225 --diag_wrap=off

Regards

Puay Teck

0 George Mock over 11 years ago in reply to Ng Teck

TI__Guru**** 250180 points

I think you presume the compiler uses a floating point divide instruction. That is not the case. The compiler calls a RTS routine to perform floating point divide. The effect of dividing by zero does not appear in the FAUCR register.

Thanks and regards,

-George

0 Ng Teck over 11 years ago in reply to George Mock

Prodigy 40 points

Ok, thanks for the help!

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C6678 FAUCR not showing DIV0 set in test program