RE: TPU output frequency

Basically, both the PWMHI and PWMPER are set to count the TPU clocks
(setup seperately).  PWMPER should be 0x8000 or less and is simply TPU
clock frequency divided by desired PWM frequency.  PWMHI is the (duty
cycle) percentage of PWMPER i.e. assume a 10MHz TPU clock and a 100kHz,
50% PWM is required, then 
 
PWMPER = 10M/100k = 100
PWMHI = 50% of PWMPER = 50
 
The frequency range is as follows:
lowest frequency = TPU clock freq / 0x8000
highest frequency - best case is sys clock / 32 or less if a single
channel is running, but this will be reduced when additional channels
are running.
 
Please refer to applications note TPUPN17 for more information.
 
- Allan
 
 

	-----Original Message-----
	From: [email protected] [mailto:[email protected]] On
Behalf Of joydeep roy
	Sent: Wednesday, June 28, 2006 6:10 AM
	To: [email protected]
	Subject: [MPC500] TPU output frequency
	
	

	Hi Everyone,
	Can someone tell me what is the frequency range for a
	TPU PWM functionality? 
	And how do we calculate the values that are to be
	written into PWMHI and PWMPER fields of the parameter
	RAM? 
	If for example we want to generate a PWM output for a
	square wave of some duty cycle(say 50%) and 
	some frequency, how do we calculate the PWMHI and
	PWMPER values? 
	
	Thanks and regards
	Joy
	
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