Why status register take the program into forever chk mode?

Anonymous · ‎Aug 07, 2017

Hello Every body,

I am doing SPI communication between Pi and PSOC 5LP.

I placed a command

while(!(SPIS_ReadTxStatus() & SPIS_STS_SPI_DONE));

But by doing this, my program just takes too long to fulfill the condition and when I replace the above condition with just:

while(!(SPIS_STS_SPI_DONE));

It does not!

I wonder why it is behaving so wierd?

Looking forward to your answers!

Bob_Marlowe · ‎Aug 07, 2017

while(!(SPIS_STS_SPI_DONE));

The above is testing a constant value for zero. SPIS_STS_SPI_DONE is a #defined value to check for a bit pattern. Checking with
while(!(SPIS_ReadTxStatus() & SPIS_STS_SPI_DONE));
will indeed consume MIPS. Think about to use a "callback macro". Look for that term in SPI datasheet and in Creator help.

Bob

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Why status register take the program into forever chk mode?

Why status register take the program into forever chk mode?

Re: Why status register take the program into forever chk mode?