CC3120 Datasheet, PDF (28/57 Pages) Texas Instruments – SimpleLink Wi-Fi Wireless Network Processor Internet-of-Things Solution for MCU Applications

CC3120
SWAS034 – FEBRUARY 2017
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4.15 Host UART
The SimpleLink device requires the UART configuration described in Table 4-14.
Table 4-14. SimpleLink UART Configuration
PROPERTY
SUPPORTED CC3120R CONFIGURATION
Baud rate
115200 bps, no auto-baud rate detection, can be changed by the host up to 3 Mbps using a special command
Data bits
8 bits
Flow control
CTS/RTS
Parity
None
Stop bits
1
Bit order
LSBit first
Host interrupt polarity
Active high
Host interrupt mode
Endianness
Rising edge or level 1
Little-endian only⁽¹⁾
(1) The SimpleLink device does not support automatic detection of the host length while using the UART interface.
4.15.1 5-Wire UART Topology
Figure 4-17 shows the typical 5-wire UART topology comprised of four standard UART lines plus one IRQ
line from the device to the host controller to allow efficient low-power mode.
nRTS
nRTS
HOST MCU
UART
nCTS
TX
RX
nCTS
TX
RX
CC3120R SL
UART
HOST_INTR(IRQ)
HOST_INTR(IRQ)
Copyright © 2017, Texas Instruments Incorporated
Figure 4-17. Typical 5-Wire UART Topology
This topology is recommended because the configuration offers the maximum communication reliability
and flexibility between the host and the SimpleLink device.
4.15.2 4-Wire UART Topology
The 4-wire UART topology eliminates the host IRQ line (see Figure 4-18). Using this topology requires
meeting one of the following conditions:
• The host is always awake or active.
• The host goes to sleep, but the UART module has receiver start-edge detection for auto wakeup and
does not lose data.
nRTS
nRTS
HOST MCU
UART
nCTS
TX
RX
nCTS
TX
CC3120R SL
UART
RX
H_IRQ
X
H_IRQ
Copyright © 2017, Texas Instruments Incorporated
Figure 4-18. 4-Wire UART Configuration
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Specifications
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