XR18W750
WIRELESS UART CONTROLLER
REV. 1.0.0
3.13
Auto CTS Flow Control
Automatic CTS flow control is used to prevent data overrun to the remote receiver FIFO. The CTS# input is
monitored to suspend/restart the local transmitter. The auto CTS flow control feature is selected to fit specific
application requirement (see Figure 9 ):
? Enable auto CTS flow control using EFR bit-7.
If using the Auto CTS interrupt:
? Enable CTS interrupt through IER bit-7 (after setting EFR bit-4). The UART issues an interrupt when the
CTS# pin is de-asserted (HIGH): ISR bit-5 will be set to 1, and UART will suspend transmission as soon as
the stop bit of the character in process is shifted out. Transmission is resumed after the CTS# input is re-
asserted (LOW), indicating more data may be sent.
F IGURE 9. A UTO RTS AND CTS F LOW C ONTROL O PERATION
Local UART
UARTA
Remote UART
UARTB
Receiver FIFO
Trigger Reached
Auto RTS
Trigger Level
Transmitter
Auto CTS
Monitor
RXA
RTSA#
TXA
CTSA#
TXB
CTSB#
RXB
RTSB#
Transmitter
Auto CTS
Monitor
Receiver FIFO
Trigger Reached
Auto RTS
Trigger Level
Assert RTS# to Begin
RTSA#
1
Transmission
ON
OFF
10
ON
2
7
CTSB#
3
ON
8
OFF
11
ON
TXB
Data Starts
4
6
Suspend
Restart
9
RXA FIFO
INTA
(RXA FIFO
Interrupt)
Receive
Data
RX FIFO
Trigger Level
5
RTS High
Threshold
RTS Low
Threshold
12
RX FIFO
Trigger Level
RTSCTS1
The local UART (UARTA) starts data transfer by asserting RTSA# (1). RTSA# is normally connected to CTSB# (2) of
remote UART (UARTB). CTSB# allows its transmitter to send data (3). TXB data arrives and fills UARTA receive FIFO
(4). When RXA data fills up to its receive FIFO trigger level, UARTA activates its RXA data ready interrupt (5) and con-
tinues to receive and put data into its FIFO. If interrupt service latency is long and data is not being unloaded, UARTA
monitors its receive data fill level to match the upper threshold of RTS delay and de-assert RTSA# (6). CTSB# follows
(7) and request UARTB transmitter to suspend data transfer. UARTB stops or finishes sending the data bits in its trans-
mit shift register (8). When receive FIFO data in UARTA is unloaded to match the lower threshold of RTS delay (9),
UARTA re-asserts RTSA# (10), CTSB# recognizes the change (11) and restarts its transmitter and data flow again until
next receive FIFO trigger (12). This same event applies to the reverse direction when UARTA sends data to UARTB
with RTSB# and CTSA# controlling the data flow.
16
相关PDF资料
XRP2526EVB BOARD EVAL POWER SWITCH XRP2526
XRP2528EVB BOARD EVAL POWER SWITCH XRP2528
XT800SM GAS TRIGGER TUBE 800V SMD
YMCRPR8C25 REF PLATFORM MOTOR CTRL R8C/25
ZB3251 INLINE FUSE HOLDER PLASTIC BODY
ZB3260 INLINE FUSE HOLDER BAKELITE BODY
ZB3270 PANEL MOUNT FUSE HOLDER
ZEN056V130A24GS POLYZEN 5.6V PPTC/ZENER SMD
相关代理商/技术参数
XR18W750IL48 制造商:EXAR 制造商全称:EXAR 功能描述:WIRELESS UART CONTROLLER
XR18W750IL48-F 功能描述:UART 接口集成电路 UART RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel
XR18W750IL48TR-F 功能描述:UART 接口集成电路 XR18W750IL48TR-F RoHS:否 制造商:Texas Instruments 通道数量:2 数据速率:3 Mbps 电源电压-最大:3.6 V 电源电压-最小:2.7 V 电源电流:20 mA 最大工作温度:+ 85 C 最小工作温度:- 40 C 封装 / 箱体:LQFP-48 封装:Reel
XR18W753 制造商:EXAR 制造商全称:EXAR 功能描述:SINGLE CHIP 868MHZ TO 956MHZ RF TRANSCEIVER
XR18W753IL48 制造商:EXAR 制造商全称:EXAR 功能描述:SINGLE CHIP 868MHZ TO 956MHZ RF TRANSCEIVER
XR18W753IL48-F 功能描述:射频接收器 UART RoHS:否 制造商:Skyworks Solutions, Inc. 类型:GPS Receiver 封装 / 箱体:QFN-24 工作频率:4.092 MHz 工作电源电压:3.3 V 封装:Reel
XR18W753L48-0A-EB 功能描述:界面开发工具 900MHz RF EVAL Board RoHS:否 制造商:Bourns 产品:Evaluation Boards 类型:RS-485 工具用于评估:ADM3485E 接口类型:RS-485 工作电源电压:3.3 V
XR1901SN 制造商:Electro-Term/Hollingsworth 功能描述: 制造商:Electro-Term/Hollingsworth 功能描述:16-14awg No. 6 stud ring terminal - FAC STK