CEC control register
| CECEN | CEC Enable The CECEN bit is set and cleared by software. CECEN=1 starts message reception and enables the TXSOM control. CECEN=0 disables the CEC peripheral, clears all bits of CEC_CR register and aborts any on-going reception or transmission. |
| TXSOM | Tx Start Of Message TXSOM is set by software to command transmission of the first byte of a CEC message. If the CEC message consists of only one byte, TXEOM must be set before of TXSOM. Start-Bit is effectively started on the CEC line after SFT is counted. If TXSOM is set while a message reception is ongoing, transmission will start after the end of reception. TXSOM is cleared by hardware after the last byte of the message is sent with a positive acknowledge (TXEND=1), in case of transmission underrun (TXUDR=1), negative acknowledge (TXACKE=1), and transmission error (TXERR=1). It is also cleared by CECEN=0. It is not cleared and transmission is automatically retried in case of arbitration lost (ARBLST=1). TXSOM can be also used as a status bit informing application whether any transmission request is pending or under execution. The application can abort a transmission request at any time by clearing the CECEN bit. Note: TXSOM must be set when CECEN=1 TXSOM must be set when transmission data is available into TXDR HEADERs first four bits containing own peripheral address are taken from TXDR[7:4], not from CEC_CFGR.OAR which is used only for reception |
| TXEOM | Tx End Of Message The TXEOM bit is set by software to command transmission of the last byte of a CEC message. TXEOM is cleared by hardware at the same time and under the same conditions as for TXSOM. Note: TXEOM must be set when CECEN=1 TXEOM must be set before writing transmission data to TXDR If TXEOM is set when TXSOM=0, transmitted message will consist of 1 byte (HEADER) only (PING message) |