Hi,
I had a Rabbit 3400 running at 29.4M Hz. With 512K Flash Memory and
512K SRAM. I had read PWM_Test.c sample program. The sample is using
10KHz PWM cycle.
Can I known what is the maximum PWM frequency that RCM3400 can do??
How to calculate the minimum and maximum PWM frequency??
Many thanks...
Regards,
CF
PWM max frequency
Started by ●July 11, 2005
Reply by ●July 12, 20052005-07-12
Max. PWM frequency is /4 of clock. In your case 7.35MHz. Mind you,
that's the PWM base clock. If you use the full 10-bit PWM this will
get you a 7.35MHz/1024 = 7.177Hz PWM frequency. Using 8-bit PWM it
goes up to 28.710Hz.
Use the TAT9R register to change the PWM base frequency:
Example: WrPortI(TAT9R, &TAT9RShadow, 0);
(change the 0 to any divider you want. Note: divider = value+1)
But of course, you can only reduce the PWM base clock.
Rudi
www.x-graph.be the next generation Rabbit SBC with (Color TFT) LCD
--- In rabbit-semi@rabb..., "chan_fongtan" <chan_fongtan@y...>
wrote:
> Hi,
>
> I had a Rabbit 3400 running at 29.4M Hz. With 512K Flash Memory and
> 512K SRAM. I had read PWM_Test.c sample program. The sample is using
> 10KHz PWM cycle.
>
> Can I known what is the maximum PWM frequency that RCM3400 can do??
> How to calculate the minimum and maximum PWM frequency??
>
> Many thanks...
>
> Regards,
> CF
that's the PWM base clock. If you use the full 10-bit PWM this will
get you a 7.35MHz/1024 = 7.177Hz PWM frequency. Using 8-bit PWM it
goes up to 28.710Hz.
Use the TAT9R register to change the PWM base frequency:
Example: WrPortI(TAT9R, &TAT9RShadow, 0);
(change the 0 to any divider you want. Note: divider = value+1)
But of course, you can only reduce the PWM base clock.
Rudi
www.x-graph.be the next generation Rabbit SBC with (Color TFT) LCD
--- In rabbit-semi@rabb..., "chan_fongtan" <chan_fongtan@y...>
wrote:
> Hi,
>
> I had a Rabbit 3400 running at 29.4M Hz. With 512K Flash Memory and
> 512K SRAM. I had read PWM_Test.c sample program. The sample is using
> 10KHz PWM cycle.
>
> Can I known what is the maximum PWM frequency that RCM3400 can do??
> How to calculate the minimum and maximum PWM frequency??
>
> Many thanks...
>
> Regards,
> CF
