It has taken me about 3 weeks to finally get this running. Thanks to mikech for the final clue.
The attached code sets up a PWM using sysclk functions to setup the system/peripheral clocks rather than power manager. Once the period is set, the duty cycle can be changed on the fly by calling a "pwm_update_local()" function.
My hope is that this will save anyone else trying to setup a UC3A PWM.
//conf_clock.h set cpu to 66 MHz
#ifndef CONF_CLOCK_H_INCLUDED
#define CONF_CLOCK_H_INCLUDED
#define CONFIG_SYSCLK_SOURCE SYSCLK_SRC_PLL0
/* Fbus = Fsys / (2 ^ BUS_div) */
#define CONFIG_SYSCLK_CPU_DIV 0
#define CONFIG_SYSCLK_PBA_DIV 0
#define CONFIG_SYSCLK_PBB_DIV 0
#define CONFIG_USBCLK_SOURCE USBCLK_SRC_PLL1
#define CONFIG_USBCLK_DIV 1
#define CONFIG_PLL0_SOURCE PLL_SRC_OSC0
#define CONFIG_PLL0_MUL 16 //(48000000UL / BOARD_OSC0_HZ)
#define CONFIG_PLL0_DIV 2
#define CONFIG_PLL1_SOURCE PLL_SRC_OSC0
#define CONFIG_PLL1_MUL (48000000UL / BOARD_OSC0_HZ)
#define CONFIG_PLL1_DIV 1
#endif /* CONF_CLOCK_H_INCLUDED */
-----------------------------------------------------------
//user_board.h
#ifndef USER_BOARD_H
#define USER_BOARD_H
#include <conf_board.h>
/* Clock Speed */
#define APPLI_CPU_SPEED 66000000
#define APPLI_PBA_SPEED 66000000
/* These are documented in services/basic/clock/uc3b0_b1/osc.h */
#define BOARD_OSC0_HZ 12000000
#define BOARD_OSC0_STARTUP_US 17000
#define BOARD_OSC0_IS_XTAL true
#define BOARD_OSC32_HZ 32768
#define BOARD_OSC32_STARTUP_US 71000
#define BOARD_OSC32_IS_XTAL true
#define FOSC0 12000000
#define CLOCK_PBA_FREQ 66000000
#define FPR_PWM AVR32_PIN_PB19
#define FPR_PWM_PIN AVR32_PWM_0_PIN//AVR32_PWM_0_0_PIN
#define FPR_PWM_FUNCTION AVR32_PWM_0_FUNCTION//AVR32_PWM_0_0_FUNCTION
#define FPR_PWM_CHANNEL_ID 0
void pmw_update_local(int duty);
void pwm_init_local(void);
#endif // USER_BOARD_H
--------------------------------------------------------------------------
//init.c
#include <asf.h>
#include <board.h>
#include <conf_board.h>
#include <pwm.h>
#include <sysclk.h>
#include <user_board.h>
void IO_Init(void);
void pwm_init_local(void);
void board_init(void)
{
sysclk_init();
gpio_local_init();
delay_init(66000000UL);
pwm_init_local();
IO_Init();
}
void IO_Init(void)
{
-----------------------------------------------------------------
//main.c
#include <asf.h>
#include <delay.h>
#include <pwm.h>
#include <sysclk.h>
#include <user_board.h>
unsigned int channel_id;
int main (void)
{
int c;
board_init();
pwm_opt_t pwm_opt; // PWM option config.
avr32_pwm_channel_t pwm_channel = { .ccnt = 0 }; // One channel config.
while (1)
{ //test changing PWM duty
for (c=1;c<999;c++)
{
pmw_update_local(c); // Change the channel duty cycle
delay_ms(10); //delay between duty cycle changes
}
}
}
------------------------------------------------------------------
//pwm_code.c
#include <asf.h>
#include <delay.h>
#include <pwm.h>
#include <sysclk.h>
#include <user_board.h>
unsigned int channel_id;
void pwm_init_local(void)
{
pwm_opt_t pwm_opt; // PWM option config.
avr32_pwm_channel_t pwm_channel = { .ccnt = 0 }; // One channel config.
channel_id =FPR_PWM_CHANNEL_ID;
gpio_enable_module_pin(FPR_PWM_PIN, FPR_PWM_FUNCTION);
// PWM controller configuration.
pwm_opt.diva = AVR32_PWM_DIVA_CLK_OFF;
pwm_opt.divb = AVR32_PWM_DIVB_CLK_OFF;
pwm_opt.prea = AVR32_PWM_PREA_MCK;
pwm_opt.preb = AVR32_PWM_PREB_MCK;
pwm_init(&pwm_opt);
pwm_channel.CMR.calg = PWM_MODE_LEFT_ALIGNED; // Channel mode.
pwm_channel.CMR.cpol = PWM_POLARITY_LOW; // Channel polarity.
pwm_channel.CMR.cpd = 0;//PWM_UPDATE_DUTY; // Update Duty Cycle
pwm_channel.CMR.cpre = AVR32_PWM_CPRE_MCK_DIV_4; //AVR32_PWM_CPRE_MCK_DIV_256; // Channel prescaler.
pwm_channel.cdty = 500; // Channel duty cycle, should be < CPRD.
pwm_channel.cprd = 1000; // Channel period.
pwm_channel.cupd = 0; // Channel update not used here.
pwm_channel_init(channel_id, &pwm_channel); // Set channel configuration to channel 0.
pwm_start_channels(1 << channel_id); // Start channel 0.
}
void pmw_update_local(int duty) //update the PWM duty cycle
{
pwm_opt_t pwm_opt; // PWM option config.
avr32_pwm_channel_t pwm_channel = { .ccnt = 0 }; // One channel config.
pwm_channel.CMR.cpre = AVR32_PWM_CPRE_MCK_DIV_4; //AVR32_PWM_CPRE_MCK_DIV_256; // Channel prescaler.
pwm_channel.cupd = duty; // Channel duty cycle, should be < CPRD.
pwm_async_update_channel(channel_id,&pwm_channel);
}