RMT TX synchronous register
| CH0 | Set this bit to enable CHANNEL0 to start sending data synchronously with other enabled channels. |
| CH1 | Set this bit to enable CHANNEL1 to start sending data synchronously with other enabled channels. |
| CH2 | Set this bit to enable CHANNEL2 to start sending data synchronously with other enabled channels. |
| CH3 | Set this bit to enable CHANNEL3 to start sending data synchronously with other enabled channels. |
| EN | This register is used to enable multiple of channels to start sending data synchronously. |