UART/Autobaud Control and Status Registers
12-19
UART Devices
Table 12–13. UART/Autobaud Registers (Continued)
Register
Access
Size
Description
MSR
Modem status
8-bit
R
IER
Interrupt enable (IER)
8-bit
R/W
IIR
Interrupt identification (IIR)
8-bit
R
EFR
Enhanced feature
8-bit
R/W
XON1
XON1
8-bit
R/W
XON2
XON2
8-bit
R/W
XOFF1
XOFF1
8-bit
R/W
XOFF2
XOFF2
8-bit
R/W
SPR
Scratchpad
8-bit
R/W
DLL
Divisor latch low
8-bit
R/W
DLH
Divisor latch high
8-bit
R/W
TCR
Transmission control
8-bit
R/W
TLR
Trigger level
8-bit
R/W
MDR1
Mode definition 1
8-bit
R/W
UASR
UART autobauding status
8-bit
R
OSC_12M_SEL
12-MHz oscillator select
8-bit
R
MVR
Module version
8-bit
R
The receiver section consists of the receiver holding register (RHR) and the
receiver shift register. The RHR is actually a 64-byte FIFO. The receiver shift
register receives serial data from RX input. The data is converted to parallel
data and moved to the RHR. If the FIFO is disabled, location zero of the FIFO
is used to store the single data character.
Note:
If overflow occurs, data in the RHR is not overwritten.