GSM/GPRS Module
M85 Hardware Design
M85_Hardware_Design Confidential / Released 36 / 92
VRTC
Large Capacitance
Capacitor
Module
RTC Core
1.5K
Figure 16: RTC Supply from a Capacitor
The following figure shows the charging characteristics of a coin-type rechargeable battery
XH414H-IV01E from Seiko.
Figure 17: Charging Characteristics of Seiko
’
s XH414H-IV01E
3.7. Serial Interfaces
The module provides three serial ports: UART Port, Debug Port and Auxiliary UART Port. The module is
designed as a DCE (Data Communication Equipment), following the traditional DCE-DTE (Data Terminal
Equipment) connection. Autobauding function supports baud rate from 4800bps to 115200bps.
The UART Port:
TXD: Send data to RXD of DTE.
Quectel
Confidential