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RM0365
Universal synchronous asynchronous receiver transmitter (USART)
901
Bits 20:16
DEDT[4:0]
: Driver Enable de-assertion time
This 5-bit value defines the time between the end of the last stop bit, in a transmitted
message, and the de-activation of the DE (Driver Enable) signal. It is expressed in sample
time units (1/8 or 1/16 bit duration, depending on the oversampling rate).
If the USART_TDR register is written during the DEDT time, the new data is transmitted only
when the DEDT and DEAT times have both elapsed.
This bit field can only be written when the USART is disabled (UE=0).
Note: If the Driver Enable feature is not supported, this bit is reserved and must be kept
cleared. Please refer to
Section 29.4: USART implementation on page 837
Bit 15
OVER8
: Oversampling mode
0: Oversampling by 16
1: Oversampling by 8
This bit can only be written when the USART is disabled (UE=0).
Note: In LIN, IrDA and modes, this bit must be kept cleared.
Bit 14
CMIE
: Character match interrupt enable
This bit is set and cleared by software.
0: Interrupt is inhibited
1: A USART interrupt is generated when the CMF bit is set in the USART_ISR register.
Bit 13
MME
: Mute mode enable
This bit activates the mute mode function of the USART. when set, the USART can switch
between the active and mute modes, as defined by the WAKE bit. It is set and cleared by
software.
0: Receiver in active mode permanently
1: Receiver can switch between mute mode and active mode.
Bit 12
M0
: Word length
This bit, with bit 28 (M1), determines the word length. It is set or cleared by software. See Bit
28 (M1) description.
This bit can only be written when the USART is disabled (UE=0).
Bit 11
WAKE
: Receiver wakeup method
This bit determines the USART wakeup method from Mute mode. It is set or cleared by
software.
0: Idle line
1: Address mark
This bit field can only be written when the USART is disabled (UE=0).
Bit 10
PCE
: Parity control enable
This bit selects the hardware parity control (generation and detection). When the parity
control is enabled, the computed parity is inserted at the MSB position (9th bit if M=1; 8th bit
if M=0) and parity is checked on the received data. This bit is set and cleared by software.
Once it is set, PCE is active after the current byte (in reception and in transmission).
0: Parity control disabled
1: Parity control enabled
This bit field can only be written when the USART is disabled (UE=0).
Bit 9
PS
: Parity selection
This bit selects the odd or even parity when the parity generation/detection is enabled (PCE
bit set). It is set and cleared by software. The parity will be selected after the current byte.
0: Even parity
1: Odd parity
This bit field can only be written when the USART is disabled (UE=0).