PLL configuration register
| PLLSRC | PLL input clock source  |  
| PLLM | Division factor M of the PLL input clock divider  |  
| PLLN | PLL frequency multiplication factor N  |  
| PLLPEN | PLLPCLK clock output enable  |  
| PLLP | PLL VCO division factor P for PLLPCLK clock output  |  
| PLLQEN | PLLQCLK clock output enable  |  
| PLLQ | PLL VCO division factor Q for PLLQCLK clock output  |  
| PLLREN | PLLRCLK clock output enable  |  
| PLLR | PLL VCO division factor R for PLLRCLK clock output  |