ISD94100 Series Technical Reference Manual
Sep 9, 2019
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of 928
Rev1.09
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ICA
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NCE
M
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U
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UART0_nCTS pin
input
Active
UART0_nCTS pin input status of UART function mode
D0
D1
D2
D3
D4
D5
D6
D7
P
Start
bit
Stop
bit
UART0_TXD pin
output
MODEMINT interrupt
Clear by softwave
Clear by softwave
Idle
Idle
TX output
delay
(default)
CTSSTS
(UART_MODEMSTS[4])
CTSACTLV=0
CTSACTLV=1
CTSDETF
MODEMINT interrupt
TX stop
Inactive
Figure 6.12-12 UART nCTS Auto-Flow Control Enabled
As shown in Figure 6.12-13, in UART nRTS auto-flow control mode (ATORTSEN
(UART_INTEN[12])=1), the nRTS internal signal is controlled by UART FIFO controller with
RTSTRGLV(UART_FIFO[19:16]) trigger level.
Setting RTSACTLV (UART_MODEM[9]) can control the nRTS pin output is inverse or non-inverse
from nRTS signal. User can read the RTSSTS (UART_MODEM[13]) bit to get real nRTS pin output
voltage logic status.
RTSACTLV = 0
nRTS Signal
(internal signal)
Active
Byte(i)
Byte (i +n)
Start
bit
UART0_RXD pin
input
(from external)
nRTS inactive
delay
External
delay
Start
bit
The Bytes
Number Stored
In FIFO
<
The Bytes Number
Stored In FIFO
=
UART0_nRTS pin output status of UART function mode, nRTS auto - flow control enabled
RTSTRGLV
(UART_FIFO[19:16])
RTSTRGLV
(UART_FIFO[19:16])
RTSSTS
(UART_MODEM[13])
UART0_nRTS pin
output
RTSACTLV = 1
(Default)
Figure 6.12-13 UART nRTS Auto-Flow Control Enabled
As shown in Figure 6.12-14, in software mode (ATORTSEN(UART_INTEN[12])=0), the nRTS flow