Async peripheral clock control
| RESERVED | Reserved. Read value is undefined, only zero should be written. |
| USART0 | Controls the clock for USART0. 0 = Disable; 1 = Enable. |
| USART1 | Controls the clock for USART1. 0 = Disable; 1 = Enable. |
| USART2 | Controls the clock for USART2. 0 = Disable; 1 = Enable. |
| USART3 | Controls the clock for USART3. 0 = Disable; 1 = Enable. |
| I2C0 | Controls the clock for I2C0. 0 = Disable; 1 = Enable. |
| I2C1 | Controls the clock for I2C1. 0 = Disable; 1 = Enable. |
| I2C2 | Controls the clock for I2C2. 0 = Disable; 1 = Enable. |
| RESERVED | Reserved. Read value is undefined, only zero should be written. |
| SPI0 | Controls the clock for SPI0. 0 = Disable; 1 = Enable. |
| SPI1 | Controls the clock for SPI1. 0 = Disable; 1 = Enable. |
| RESERVED | Reserved. Read value is undefined, only zero should be written. |
| TIMER0 | Controls the clock for TIMER0. 0 = Disable; 1 = Enable. |
| TIMER1 | Controls the clock for TIMER1. 0 = Disable; 1 = Enable. |
| FRG0 | Controls the clock for the Fractional Rate Generator used with the USARTs. 0 = Disable; 1 = Enable. |
| RESERVED | Reserved. Read value is undefined, only zero should be written. |