Gsm Serial Interface - SimCom SIM548C HD V1.01 Hardware Design

SIM548C Hardware Design
Note:
Gold-capacitance backup
Some suitable coin cells are the electric double layer capacitors available from Seiko (XC621),
or from Panasonic (EECEM0E204A). They have a small physical size (6.8mm diameter) and a
nominal capacity of 0.2F to 0.3F, giving hours of backup time.

3.9 GSM Serial interface

Table 13: Pin definition of the serial interfaces
Name
DCD
DTR
RXD
Serial port
TXD
RTS
CTS
RI
DBG_RXD
Debug port
DBG_TXD
SIM548C_HD_V1.01
Figure 16: Seiko TS621 Charge Characteristic
Pin
25
27
29
31
33
35
37
36
38
Function
Data carrier detection
Data terminal ready
Receive data
Transmit data
Request to send
Clear to send
Ring indicator
Receive data
Transmit data
44
09.05.2008