Assembler instruction TPF takes 2 clock cycles

ariaveta — Tue, 02 Oct 2007 16:25:31 GMT

Hello,
I need to write a routine to generate precise waveform, and I plan to use GPIO. I tried to use QSPI for this purpose but I didn't manage to have no clock delays between consecutive data.

I'm using the TPF (trap false) assembler instruction to align time in my code. I read on the Coldfire programmer manual that the TPF is better than NOP because it lasts exactly 1 clock cycle. I made some test and I found that I could not get 1 clock cycle delay, but only multiple of 2 clock cycles.

I mean that a single TPF lasts 0 clock cycle, 2 TPF last 2 clock cycle, and I have no way to get, say, 3 clock cycles.

Am I missing something?

Thanks,
Marco

Re: Assembler instruction TPF takes 2 clock cycles

macl — Tue, 02 Oct 2007 20:58:01 GMT

Hi,

Please tell us what device you are programming. Always add this information to the message subject line.

Thanks,

Mac

Re: Assembler instruction TPF takes 2 clock cycles - MCF52235

ariaveta — Tue, 02 Oct 2007 21:42:04 GMT

Sorry,
I'm programming the MCF52235.

Thanks,
Marco

topic Re: Assembler instruction TPF takes 2 clock cycles in ColdFire/68K Microcontrollers and Processors

Assembler instruction TPF takes 2 clock cycles

Re: Assembler instruction TPF takes 2 clock cycles

Re: Assembler instruction TPF takes 2 clock cycles - MCF52235