UART Registers
19.5.1.3 Interrupt Enable Register (IER) - UART Mode
The interrupt enable register (IER) can be programmed to enable/disable any interrupt. There are seven
types of interrupt in this mode: receiver error, RHR interrupt, THR interrupt, XOFF received and CTS/RTS
change of state from low to high. Each interrupt can be enabled/disabled individually. There is also a sleep
mode enable bit. The UART interrupt enable register (IER) is shown in
and described in
.
Figure 19-36. UART Interrupt Enable Register (IER)
15
8
Reserved
R-0
7
6
5
4
3
2
1
0
CTSIT
RTSIT
XOFFIT
SLEEPMODE
MODEMSTSIT
LINESTSIT
THRIT
RHRIT
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -n = value after reset
Table 19-32. UART Interrupt Enable Register (IER) Field Descriptions
Bit
Field
Value
Description
15-8
Reserved
0
Reserved.
7
CTSIT
Can be written only when EFR[4] = 1.
0
Disables the CTS interrupt.
1
Enables the CTS interrupt.
6
RTSIT
Can be written only when EFR[4] = 1.
0
Disables the RTS interrupt.
1
Enables the RTS interrupt.
5
XOFFIT
Can be written only when EFR[4] = 1.
0
Disables the XOFF interrupt.
1
Enables the XOFF interrupt.
4
SLEEPMODE
Can be only written when EFR[4] = 1.
0
Disables sleep mode.
1
Enables sleep mode (stop baud rate clock when the module is inactive).
3
MODEMSTSIT
0
Disables the modem status register interrupt.
1
Enables the modem status register interrupt
2
LINESTSIT
0
Disables the receiver line status interrupt.
1
Enables the receiver line status interrupt.
1
THRIT
0
Disables the THR interrupt.
1
Enables the THR interrupt.
0
RHRIT
0
Disables the RHR interrupt and time out interrupt.
1
Enables the RHR interrupt and time out interrupt.
3508
Universal Asynchronous Receiver/Transmitter (UART)
SPRUH73H – October 2011 – Revised April 2013
Copyright © 2011–2013, Texas Instruments Incorporated