ISD94100 Series Technical Reference Manual
Sep 9, 2019
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Rev1.09
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UART FIFO Control Register (UART_FIFO)
Register
Offset
R/W Description
Reset Value
UART_FIFO
U0x08
R/W UART FIFO Control Register
0x0000_0101
31
30
29
28
27
26
25
24
Reserved
23
22
21
20
19
18
17
16
Reserved
RTSTRGLV
15
14
13
12
11
10
9
8
Reserved
RXOFF
7
6
5
4
3
2
1
0
RFITL
Reserved
TXRST
RXRST
Reserved
Bits
Description
[31:20]
Reserved
Reserved. Any values read should be ignored. When writing to this field always write with
reset value.
[19:16]
RTSTRGLV
nRTS Trigger Level for Auto-flow Control Use
0000 = nRTS Trigger Level is 1 byte.
0001 = nRTS Trigger Level is 4 bytes.
0010 = nRTS Trigger Level is 8 bytes.
0011 = nRTS Trigger Level is 14 bytes.
Others = Reserved. Do not use.
Note:
This field is used for auto nRTS flow control.
[15:9]
Reserved
Reserved. Any values read should be ignored. When writing to this field always write with
reset value.
[8]
RXOFF
Receiver Disable Bit
The receiver is disabled or not (set 1 to disable receiver).
0 = Receiver Enabled.
1 = Receiver Disabled.
Note:
This bit is used for RS-485 Normal Multi-drop mode. It should be programmed before
RS485NMM (UART_ALTCTL [8]) is programmed.
[7:4]
RFITL
RX FIFO Interrupt Trigger Level
When the number of bytes in the receive FIFO equals the RFITL, the RDAIF
(UART_INTSTS[0]) will be set (if RDAIEN (UART_INTEN [0]) enabled, and an interrupt will
be generated).
0000 = RX FIFO Interrupt Trigger Level is 1 byte.
0001 = RX FIFO Interrupt Trigger Level is 4 bytes.
0010 = RX FIFO Interrupt Trigger Level is 8 bytes.
0011 = RX FIFO Interrupt Trigger Level is 14 bytes.
Others = Reserved. Do not use.
[3]
Reserved
Reserved. Any values read should be ignored. When writing to this field always write with
