N27 Hardware User Guide
Chapter 4 Application Interfaces
Copyright © Neoway Technology Co., Ltd. All rights reserved.
28
UART1_RXD.
UART0_RTS
1
51
DO
Request
to
send
Software (open) version: used as
UART1_RTS.
UART0_CTS
1
50
DI
Clear to send
Software (open) version: used as
UART1_CTS.
UART1_RTS
1
23
DO
Request
to
send
Software (open) version: used as
UART2_RTS.
UART1_CTS
1
24
DI
Clear to send
Software (open) version: used as
UART2_CTS.
UART1_RXD
1
25
DI
Data RX
Software (open) version: used as
UART2_TXD.
UART1_TXD
1
26
DO
Data TX
Software (open) version: used as
UART2_RXD.
UART2_RXD
14
DI
Data RX
Software (open) version: Do not use
these pins. Leave these pins floating.
UART2_TXD
13
DO
Data TX
N27 provides pins to configure three UART interfaces, two of which support hardware flow control. The
UART interfaces support 4 Mbps at most. The level at the interfaces is 1.8V. Figure 4-7 shows the
reference design of the UART interface.
Figure 4-7 UART connection
UART_RXD
UART_CTS
UART_RTS
N27
UART_TXD
RXD
TXD
CTS
RTS
MCU
Schematic guidelines
Note the match of signals.
The UART of N27 operates in a power domain of 1.8V. If your host MCU is not in this power domain,
add a level shifting circuit between the module and the host. The following figure shows the
