Hardware Development Guide of Module Product
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3.8.3
UART Interface
3.8.3.1
Description of PINs
ZM5202 module provides a circuit of serial communication interface UART, which
complies with the RS-232 interface protocol, and supports the 8-byte serial bus
interface or 2-byte serial interface is Via the UART interface. But the 8-byte serial
bus UART interface and the SPI bus interface are not supported simultaneously.
The module can perform the serial communication and AT instruction interaction
with external.
This UART port supports the programmable data width, programmable data stop
digit and programmable odd/even checksum, and has an independent TX and RX
FIFOs (512 bytes for each). For the normal UART application (non-Bluetooth), the
maximum baud r ate is 230400bps, the 4Mbps high baud rate is only used on
Bluetooth 2.0 application, and the default baud rate is 115200bps. The PINs are
defined as shown in Table 3-8.
Table 3-8 Definition of UART Signal
PIN
Signal
Name
Description
Function
27
UART1_CTS
UART port CTS clearing
sending
UART power level
is 1.8V.
28
UART1_RFR
UART port RFR preparing to
receive
29
UART1_TXD UART port TXT sending data
30
UART1_RXD UART port RXD data receiving
40
UART_DTR
DTE is ready
--
41
UART_RI
Ring indicator
--
42
UART_DSR
Data is ready
--
39
UART_DCD Carrier detect
--
3.8.3.2
Electric Feature
During the software interconnection process, there is a method of capturing logs,
and it is recommended that this interface be kept during the design and the testing
point be reserved. If the module is used together with the application processor, and
the PWL matches with 1.8V, the connection mode is as shown in Figure 3-7. The
