Atmel SAM4S Xplained Pro Starter and Evaluation Kit ATSAM4S-XPRO ATSAM4S-XPRO Data Sheet
Product codes
ATSAM4S-XPRO
SAM4S Series [DATASHEET]
Atmel-11100G-ATARM-SAM4S-Datasheet_27-May-14
816
36.8.12 USART Channel Status Register (SPI_MODE)
Name:
US_CSR (SPI_MODE)
Address:
0x40024014 (0), 0x40028014 (1)
Access:
Read-only
This configuration is relevant only if USART_MODE = 0xE or 0xF in “USART Mode Register” on page 798.
• RXRDY: Receiver Ready
0: No complete character has been received since the last read of US_RHR or the receiver is disabled. If characters were
being received when the receiver was disabled, RXRDY changes to 1 when the receiver is enabled.
1: At least one complete character has been received and US_RHR has not yet been read.
1: At least one complete character has been received and US_RHR has not yet been read.
• TXRDY: Transmitter Ready
0: A character is in the US_THR waiting to be transferred to the Transmit Shift Register or the transmitter is disabled. As
soon as the transmitter is enabled, TXRDY becomes 1.
1: There is no character in the US_THR.
1: There is no character in the US_THR.
• OVRE: Overrun Error
0: No overrun error has occurred since the last RSTSTA.
1: At least one overrun error has occurred since the last RSTSTA.
1: At least one overrun error has occurred since the last RSTSTA.
• TXEMPTY: Transmitter Empty
0: There are characters in either US_THR or the Transmit Shift Register, or the transmitter is disabled.
1: There are no characters in US_THR, nor in the Transmit Shift Register.
1: There are no characters in US_THR, nor in the Transmit Shift Register.
• UNRE: Underrun Error
0: No SPI underrun error has occurred since the last RSTSTA.
1: At least one SPI underrun error has occurred since the last RSTSTA.
1: At least one SPI underrun error has occurred since the last RSTSTA.
31
30
29
28
27
26
25
24
–
–
–
–
–
–
–
–
23
22
21
20
19
18
17
16
–
–
–
–
–
–
–
–
15
14
13
12
11
10
9
8
–
–
–
RXBUFF
TXBUFE
UNRE
TXEMPTY
–
7
6
5
4
3
2
1
0
–
–
OVRE
ENDTX
ENDRX
–
TXRDY
RXRDY