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fastest PWM clock source in 56F805

Started by steveroverdrive December 4, 2005
It appears that the only clock source for the PWM unit is the IPBUS,
which is always 1/2 the chip operating frequency (section 11.5.2). My
chip is running at 80 MHz, so I get a 40MHz clock at the PWM unit. I
need a faster PWM clock speed, for smaller pulse-width deltas at high
pwm rates. Is there any way in the 56F805 to clock the PWM unit at
the full chip operating frequency ? Can I send in an external clock ?
Should I switch to another DSP ?



Can you say why you need to have smaller pulse width delta's? Most
mechanical systems are too non-linear and have too much inertia to respond
to small changes. Chris P

>From: "steveroverdrive" <steveroverdrive@stev...>
>To: motoroladsp@moto...
>Subject: [motoroladsp] fastest PWM clock source in 56F805
>Date: Sun, 04 Dec 2005 18:40:14 -0000
>
>It appears that the only clock source for the PWM unit is the IPBUS,
>which is always 1/2 the chip operating frequency (section 11.5.2). My
>chip is running at 80 MHz, so I get a 40MHz clock at the PWM unit. I
>need a faster PWM clock speed, for smaller pulse-width deltas at high
>pwm rates. Is there any way in the 56F805 to clock the PWM unit at
>the full chip operating frequency ? Can I send in an external clock ?
>Should I switch to another DSP ?
>