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M0A21/M0A23 Series
May 06, 2022
Page
458
of 746
Rev 1.02
M0
A21
/M
0
A
2
3
SE
RIES
TEC
H
NICAL
RE
FEREN
C
E
M
ANUAL
UART FIFO Status Register (UART_FIFOSTS)
Register
Offset
R/W
Description
Reset Value
UART_FIFOSTS
x=0,1
U0x18
R/W
UART FIFO Status Register
0xB040_4000
31
30
29
28
27
26
25
24
TXRXACT
Reserved
RXIDLE
TXEMPTYF
Reserved
TXOVIF
23
22
21
20
19
18
17
16
TXFULL
TXEMPTY
TXPTR
15
14
13
12
11
10
9
8
RXFULL
RXEMPTY
RXPTR
7
6
5
4
3
2
1
0
Reserved
BIF
FEF
PEF
ADDRDETF
ABRDTOIF
ABRDIF
RXOVIF
Bits
Description
[31]
TXRXACT
TX and RX Active Status (Read Only)
This bit indicates TX and RX are active or inactive.
0 = TX and RX are inactive.
1 = TX and RX are active. (Default)
Note:
When TXRXDIS (UART_FUNCSEL[3]) is set and both TX and RX are in idle state,
this bit is cleared. The UART controller can not transmit or receive data at this moment.
Otherwise this bit is set.
[30]
Reserved
Reserved.
[29]
RXIDLE
RX Idle Status (Read Only)
This bit is set by hardware when RX is idle.
0 = RX is busy.
1 = RX is idle. (Default)
[28]
TXEMPTYF
Transmitter Empty Flag (Read Only)
This bit is set by hardware when TX FIFO (UART_DAT) is empty and the STOP bit of the
last byte has been transmitted.
0 = TX FIFO is not empty or the STOP bit of the last byte has been not transmitted.
1 = TX FIFO is empty and the STOP bit of the last byte has been transmitted.
Note:
This bit is cleared automatically when TX FIFO is not empty or the last byte
transmission has not completed.
[27:25]
Reserved
Reserved.
[24]
TXOVIF
TX Overflow Error Interrupt Flag
If TX FIFO (UART_DAT) is full, an additional write to UART_DAT will cause this bit to logic
1.
0 = TX FIFO is not overflow.
1 = TX FIFO is overflow.
Note:
This bit can be cleared by writing “1” to it.
[23]
TXFULL
Transmitter FIFO Full (Read Only)