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atkbldcdriver

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void setuppwm(void){
	PMC->PMC_PCER1 = 1 << 28; // turn on peripheral clock for PWM 1
	// these are pins for channels 1, 2, 3 in lo / hi pairs
	PIOD->PIO_PDR = PIO_PER_P2 | PIO_PER_P3 | PIO_PER_P4 | PIO_PER_P5 | PIO_PER_P6 | PIO_PER_P7; // disable PIO
	PIOD->PIO_ABCDSR[0] = PIO_PER_P2 | PIO_PER_P3 | PIO_PER_P4 | PIO_PER_P5 | PIO_PER_P6 | PIO_PER_P7; // enable peripheral B
	//PIOD->PIO_ABCDSR[1] // already these are 0s, we want that [01] is peripheral B

	// PREA Clock is Peripheral Clock / 64
	// PREA Clock supplies Clock A, Clock A is PREA / 24
	// Clock B is off
	PWM1->PWM_CLK = PWM_CLK_PREA(2) | PWM_CLK_DIVA(7) | PWM_CLK_DIVB_CLKB_POFF;
	// Channel 0 uses CLCKA, uses Center Aligned, has dead time, is waveform aligned (with others?)
	PWM1->PWM_CH_NUM[1].PWM_CMR  = PWM_CMR_CPRE_CLKA | PWM_CMR_CES | PWM_CMR_DTE | PWM_CMR_CALG;
	// Channel 0 uses this period
	// (2 * 2^PREA * DIVA * CPRD) / f_peripheralClock
	// so for 10kHz target frequency, we want 1 / 10000,
	// have (2 * 64 * 12 * x )/ 150000000
	// ~ spreadsheets are your friends ~
	PWM1->PWM_CH_NUM[1].PWM_CPRD = PWM_CPRD_CPRD(255);
	// set duty cycle, initially, to low
	// this is between 0 and CPRD, so it looks like shooting for a big CPRD is (y)
	PWM1->PWM_CH_NUM[1].PWM_CDTY = PWM_CDTY_CDTY(1);
	// configure deadtime generator, between 0 and CPRD - CDTY
	PWM1->PWM_CH_NUM[1].PWM_DT = PWM_DT_DTH(2) | PWM_DT_DTL(2);
	// configure update mode
	// mode 1 is 'manual write of double buffer registers and automatic update of synchronous channels'
	// other modes are for manual write / manual  update and DMA mode
	// also add sync. channels - spec that 0, 1, 2 are ~ on the same wavelength, man ~
	PWM1->PWM_SCM = PWM_SCM_UPDM_MODE1 | PWM_SCM_SYNC0;

	// now, boot it up
	PWM1->PWM_ENA = PWM_ENA_CHID1; // just channel 0 for now

	// understand: compare? clock? update? duty cycle register? period register?
}

int main (void)
{
	board_init();
	sysclk_init();
	wdt_disable(WDT);

	setuppwm();

	PMC->PMC_PCER0 = 1 << ID_PIOA;

	PIOA->PIO_PER |= PIO_PER_P27;
	PIOA->PIO_OER = PIO_PER_P27;

	startupflash();

	while(1){
		// to update, must use duty update register, not just 'duty'
		PWM1->PWM_CH_NUM[1].PWM_CDTYUPD = PWM_CDTY_CDTY(20);
		delay_ms(100);
		PWM1->PWM_CH_NUM[1].PWM_CDTYUPD = PWM_CDTY_CDTY(155);
		delay_ms(50);
	}
}
	NVIC_DisableIRQ(UART1_IRQn);
	NVIC_ClearPendingIRQ(UART1_IRQn);
	NVIC_SetPriority(UART1_IRQn, 9);
	NVIC_EnableIRQ(UART1_IRQn);
void UART1_Handler(){
	if(UART1->UART_SR & UART_SR_RXRDY){
		uint8_t data = UART1->UART_RHR; // read the incoming data
		while(!(UART1->UART_SR & UART_SR_TXRDY)); // hang-10 to make sure the UART is ready to send
		UART1->UART_THR = data;
	} else {
		//
	}
}