STMicroelectronics STM32F05 series User Manual

Universal synchronous asynchronous receiver transmitter (USART) RM0091
618/742 Doc ID 018940 Rev 1
25.7.3 Control register 3 (USART_CR3)
Address offset: 0x08
Reset value: 0x0000
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
Res Res Res Res Res Res Res Res Res WUFIE WUS[2:0] SCARCNT2:0]
Res
rw rw rw rw rw rw
1514131211109876543210
DEP DEM DDRE
OVR
DIS
ONE
BIT
CTSIE CTSE RTSE DMAT DMAR SCEN NACK
HD
SEL
IRLP IREN EIE
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bits 31:23 Reserved, must be kept at reset value.
Bit 22 WUFIE: Wakeup from Stop mode interrupt enable
This bit is set and cleared by software.
0: Interrupt is inhibited
1: An USART interrupt is generated whenever WUF=1 in the USART_ISR register
Note: 1. WUFIE must be set before entering in Stop mode.
2. The WUF interrupt is active only in Stop mode.
3. If the USART does not support the wakeup from Stop feature, this bit is reserved
and forced by hardware to ‘0’.
Bits 21:20 WUS[1:0]: Wakeup from Stop mode interrupt flag selection
This bit-field specify the event which activates the WUF (Wakeup from Stop mode flag).
00: WUF active on address match (as defined by ADD[7:0] and ADDM7)
01:Reserved.
10: WUF active on Start bit detection
11: WUF active on RXNE.
This bit field can only be written when the USART is disabled (UE=0).
Note: If the USART does not support the wakeup from Stop feature, this bit is reserved and
forced by hardware to ‘0’.
Bits 19:17 SCARCNT[2:0]: Smartcard auto-retry count
This bit-field specifies the number of retries in transmit and receive, in Smartcard mode.
In transmission mode, it specifies the number of automatic retransmission retries, before
generating a transmission error (FE bit set).
In reception mode, it specifies the number or erroneous reception trials, before generating a
reception error (RXNE and PE bits set).
This bit field must be programmed only when the USART is disabled (UE=0).
When the USART is enabled (UE=1), this bit field may only be written to 0x0, in order to
stop retransmission.
0x0: retransmission disabled - No automatic retransmission in transmit mode.
0x1 to 0x7: number of automatic retransmission attempts (before signaling error)
Note: If Smartcard mode is not supported, this bit is reserved and forced by hardware to ‘0’.
Please refer to Section 25.4: USART implementation on page 573.
Bit 16 Reserved, must be kept at reset value.

STMicroelectronics STM32F05 series Specifications

General

Brand	STMicroelectronics
Model	STM32F05 series
Category	Microcontrollers
Language	English