APB2 peripheral clock enable register (CRM_APB2EN)
| IOMUXEN | MUX function I/O clock enable |
| GPIOAEN | I/O port A clock enable |
| GPIOBEN | I/O port B clock enable |
| GPIOCEN | I/O port C clock enable |
| GPIODEN | I/O port D clock enable |
| GPIOFEN | I/O port F clock enable |
| ADC1EN | ADC1 clock enable |
| TMR1EN | Timer1 clock enable |
| SPI1EN | SPI1 clock enable |
| USART1EN | USART1 clock enable |
| TMR9EN | Timer9 clock enable |
| TMR10EN | Timer10 clock enable |
| TMR11EN | Timer11 clock enable |
| ACCEN | ACC clock enable |