24.5.8 Control C - Async Mode
This register description is valid for all modes except Master SPI mode. When the USART Communication Mode bits (CMODE) in this register are written to 'MSPI', see Control C - Master SPI Mode for the correct description.
| Name: | CTRLC |
| Offset: | 0x07 |
| Reset: | 0x00 |
| Property: | - |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| CMODE[1:0] | PMODE[1:0] | SBMODE | CHSIZE[2:0] | ||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | |
Bits 7:6 – CMODE[1:0] USART Communication Mode
Writing a 0x3 to these bits alters the available bit fields in this register, see Control C - Master SPI Mode- Master SPI Mode .
| Value | Name | Description |
|---|---|---|
| 0x0 | ASYNCHRONOUS | Asynchronous USART |
| 0x1 | SYNCHRONOUS | Synchronous USART |
| 0x2 | IRCOM | Infrared Communication |
| 0x3 | MSPI | Master SPI |
Bits 5:4 – PMODE[1:0] Parity Mode
Writing these bits enables and selects the type of parity generation.
When enabled, the Transmitter will automatically generate and send the parity of the transmitted data bits within each frame. The Receiver will generate a parity value for the incoming data, compare it to the PMODE setting, and set the Parity Error flag (PERR) in the Status register (USART.STATUS) if a mismatch is detected.
| Value | Name | Description |
|---|---|---|
| 0x0 | DISABLED | Disabled |
| 0x1 | - | Reserved |
| 0x2 | EVEN | Enabled, Even Parity |
| 0x3 | ODD | Enabled, Odd Parity |
Bit 3 – SBMODE Stop Bit Mode
The Receiver ignores this setting.
| Value | Description |
|---|---|
| 0 | 1 stop bit |
| 1 | 2 stop bits |
Bits 2:0 – CHSIZE[2:0] Character Size
| Value | Name | Description |
|---|---|---|
| 0x0 | 5BIT | 5-bit |
| 0x1 | 6BIT | 6-bit |
| 0x2 | 7BIT | 7-bit |
| 0x3 | 8BIT | 8-bit |
| 0x4 | - | Reserved |
| 0x5 | - | Reserved |
| 0x6 | 9BIT | 9-bit (Low byte first) |
| 0x7 | 9BIT | 9-bit (High byte first) |