Atmel SAM4 PMC

1.设置引脚Mode

ioport_set_pin_mode(PIO_PA17_IDX,IOPORT_MODE_MUX_B);//把PA17复用为PCK1

ioport_disable_pin(PIO_PA17_IDX);   

 

ioport_set_pin_mode(PIO_PA18_IDX,IOPORT_MODE_MUX_B);//把PA18复用为PCK2

ioport_disable_pin(PIO_PA18_IDX);

2.设置PMC，使能输出

2.1寄存器

PMC->PMC_PCK[1]  |= PMC_PCK_CSS_MCK | PMC_PCK_PRES_CLK_32;

PMC->PMC_IER  |= PMC_IER_PCKRDY1;

PMC->PMC_SCER |= PMC_SCER_PCK1;

 

PMC->PMC_PCK[2]  |= PMC_PCK_CSS_SLOW_CLK ;

PMC->PMC_IER  |= PMC_IER_PCKRDY2;

PMC->PMC_SCER |= PMC_SCER_PCK2;

2.2 库函数

pmc_switch_pck_to_pllack(1,PMC_PCK_PRES_CLK_32);

pmc_enable_pck(1);

 

pmc_switch_pck_to_sclk(2,PMC_PCK_PRES_CLK_1);

pmc_enable_pck(2);