150
1745D–ATARM–04-Nov-05
AT91M55800A
18.10.6 USART Channel Status Register
Name: US_CSR
Access Type: Read-only
Reset: 0x18
Offset: 0x14
• RXRDY: Receiver Ready (Code Label US_RXRDY)
0 = No complete character has been received since the last read of the US_RHR or the receiver is disabled.
1 = At least one complete character has been received and the US_RHR has not yet been read.
• TXRDY: Transmitter Ready (Code Label US_TXRDY)
0 = US_THR contains a character waiting to be transferred to the Transmit Shift Register, or an STTBRK command has
been requested.
1 = US_THR is empty and there is no Break request pending TSR availability.
Equal to zero when the USART is disabled or at reset. Transmitter Enable command (in US_CR) sets this bit to one.
• RXBRK: Break Received/End of Break (Code Label US_RXBRK)
0 = No Break Received nor End of Break detected since the last “Reset Status Bits” command in the Control Register.
1 = Break Received or End of Break detected since the last “Reset Status Bits” command in the Control Register.
• ENDRX: End of Receive Transfer (Code Label US_ENDRX)
0 = The End of Transfer signal from the Peripheral Data Controller channel dedicated to the receiver is inactive.
1 = The End of Transfer signal from the Peripheral Data Controller channel dedicated to the receiver is active.
• ENDTX: End of Transmit Transfer (Code Label US_ENDTX)
0 = The End of Transfer signal from the Peripheral Data Controller channel dedicated to the transmitter is inactive.
1 = The End of Transfer signal from the Peripheral Data Controller channel dedicated to the transmitter is active.
• OVRE: Overrun Error (Code Label US_OVRE)
0 = No byte has been transferred from the Receive Shift Register to the US_RHR when RxRDY was asserted since the last
“Reset Status Bits” command.
1 = At least one byte has been transferred from the Receive Shift Register to the US_RHR when RxRDY was asserted
since the last “Reset Status Bits” command.
• FRAME: Framing Error (Code Label US_FRAME)
0 = No stop bit has been detected low since the last “Reset Status Bits” command.
1 = At least one stop bit has been detected low since the last “Reset Status Bits” command.
• PARE: Parity Error (Code Label US_PARE)
1 = At least one parity bit has been detected false (or a parity bit high in multi-drop mode) since the last “Reset Status Bits”
command.
0 = No parity bit has been detected false (or a parity bit high in multi-drop mode) since the last “Reset Status Bits”
command.
31 30 29 28 27 26 25 24
– – – – – – – –
23 22 21 20 19 18 17 16
– – – – – – – –
15 14 13 12 11 10 9 8
– – – – – –
TXEMPTY TIMEOUT
7 6 5 4 3 2 1 0
PARE FRAME OVRE ENDTX ENDRX RXBRK TXRDY RXRDY