Datasheet

Receive
Character
Completed
Interrupt
Service Started,
GIE = 0
URXIFGx = 0
USPIEx = 0
URXIFGx = 1
USPIEx = 1 and
URXIEx = 1 and
GIE = 1 and
Priority Valid
GIE = 0
Priority
Too
Low
URXIFGx = 0
Wait For Next
Start
USPIEx = 0
SWRST = 1
PUC
USPIEx = 1
URXIEx = 0
SWRST = 1
Receive
Character
URXS
Clear
τ
(S)
SYNC
Valid Start Bit
Receiver Collects Character
URXSE
From URXD
PE
FE
BRK
URXEIE
URXWIE
RXWAKE
Character Received
URXIFGx
URXIEx
Interrupt Service
Requested
SWRST
PUC
UxRXBUF Read
URXSE
IRQA
SYNC = 1
Clear
www.ti.com USART Operation: SPI Mode
19.2.6.2 SPI Receive Interrupt Operation
The URXIFGx interrupt flag is set each time a character is received and loaded into UxRXBUF as shown
in Figure 19-11 and Figure 19-12. An interrupt request is generated if URXIEx and GIE are also set.
URXIFGx and URXIEx are reset by a system reset PUC signal or when SWRST = 1. URXIFGx is
automatically reset if the pending interrupt is served or when UxRXBUF is read.
Figure 19-11. Receive Interrupt Operation
Figure 19-12. Receive Interrupt State Diagram
505
SLAU144J–December 2004–Revised July 2013 USART Peripheral Interface, SPI Mode
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