
NUC126
Aug. 08, 2018
Page
740
of 943
Rev 1.03
NUC12
6 S
E
RI
E
S
T
E
CH
NI
CA
L R
E
F
E
RE
NCE
MA
NUA
L
The general event and interrupt structure is shown in below.
Clear Event
Indication
Flag
Event Condition
is met
Event
Indication
Flag
Interrupt
Enable
Clear
Set
Event Interrupt
Figure 6.19-12 Event and Interrupt Structure
Each general interrupt enable can set by RXENDIEN, RXSTIEN, TXENDIEN, and TXSTIEN of
USCI_INTEN [4:1]. The events are including receive end interrupt event, receive start interrupt event,
transmit end interrupt event, and transmit start interrupt event. For protocol-specific interrupt, it is
specified in each protocol interrupt enable register.
If a defined condition is met, an event is detected and an event indication flag becomes automatically
set. The flag stays set until it is cleared by software. If enabled, an interrupt can be generated if an
event is detected.
The registers, bits and bit fields indicate the data transfer events and control the general interrupts of a
USCI are shown in Table 6.19-3.
Table 6.19-3 Data Transfer Events and Interrupt Handling
6.19.4.7 Protocol-specific Events and Interrupts
These events are related to protocol-specific actions that are described in the corresponding protocol
chapters. The related indication flags are located in register USCI_PROTSTS. All events can be
individually enabled for the generation of the common protocol interrupt.
Event
Indication Flag
Indication Cleared By
Interrupt Enabled By
Transmit start interrupt
event
TXSTIF
(USCI_PROTSTS [1])
It is cleared by software writes 1 to
corresponding interrupt bit of
USCI_PROTSTS.
TXSTIEN
(USCI_INTEN [1])
Transmit end interrupt
event
TXENDIF
(USCI_PROTSTS [2])
TXENDIEN
(USCI_INTEN [2])
Receive start interrupt
event
RXSTIF
(USCI_PROTSTS [3])
RXSTIEN
(USCI_INTEN [3])
Receive end interrupt event
RXENDIF
(USCI_PROTSTS [4])
RXENDIEN
(USCI_INTEN [4])
Event
Indication Flag
Indication Cleared By
Interrupt Enabled
By
Protocol-specific events in
UART mode
USCI_PROTSTS [17:16] and
USCI_PROTSTS [11:5]
It is cleared by software writes 1 to
corresponding interrupt bit of
USCI_PROTSTS.
USCI_PROTIEN[2:1]
Protocol-specific events in
SPI mode
USCI_PROTSTS [9:8],
USCI_PROTSTS [6:5]
USCI_PROTIEN
[3:0]