topic AP32 Timer behaver with Cyclone in 8-bit Microcontrollers

AP32 Timer behaver with Cyclone

byteybird1 — Mon, 17 Apr 2006 00:52:39 GMT

I'm using the P&E Cyclone Pro for development. The P&E oscillator is 9.8304MHz. I'm also using the same frequency for deployment. What I have notice is that when using the Cyclone, the timer is running at twice the frequency than when the Cyclone is not connected. PTA1, PTA2 and PTB0 are used during reset by the Cyclone but not during normal execution.

Any suggestions as to what could cause the timer to running at a differece rate (factor of 2) when the Cyclone is connected.

Re: AP32 Timer behaver with Cyclone

alex_spotw — Mon, 17 Apr 2006 23:39:03 GMT

Hi:

Maybe your board runs from one oscillator in one case , and from other in the other case? Or maybe the Cyclone enables the internal PLL and the stand-alone application doesn't?

Regards,

ALex

Re: AP32 Timer behaver with Cyclone

petr — Tue, 18 Apr 2006 12:57:34 GMT

Hello
Just guessing. I don't have the cyclone pro, just multilink. However, the connection dialog of the multilink allows you to select the divider used to derive bus clock vrom the oscillator clock - 2 or 4. Make sure that you select the 4, which corresponds to the divider normal mode. The option affects the value on PTB0 pin during startup. For further explanation see datasheet of the AP32 and chapter Monitor ROM.
Regards
Petr

Re: AP32 Timer behaver with Cyclone

byteybird1 — Wed, 19 Apr 2006 09:39:41 GMT

That did the trick, thanks. I'll have to take some time and read that section. The timer clock is now the external clock divided by 4 with and without using the Cyclone Pro. But in either case the clock (external oscillator) as measure using at scope is 9.8Mhz. Setting the divide by 2 must have cause the internal divider to be set to 2 instead of the default setting of 4 when the Cyclone connected to the monitor.