User's Manual

UMTS/HSPA Module Series
UC20 User Manual
UC20_Hardware_Design Confidential / Released 42 / 84
TXS0108PWR
DCD_3.3V
RTS_3.3V
DTR_3.3V
RXD_3.3V
RI_3.3V
CTS_3.3V
TXD_3.3V
DCD
RTS
DTR
RXD
RI
CTS
TXD
DCD_1.8V
RTS_1.8V
DTR_1.8V
RXD_1.8V
RI_1.8V
CTS_1.8V
TXD_1.8V
VCCA
Module
GND GND
VDD_EXT VCCB
3.3V
DIN1
ROUT3
ROUT2
ROUT1
DIN4
DIN3
DIN2
DIN5
R1OUTB
FORCEON
/FORCEOFF
/INVALID
3.3V
DOUT1
DOUT2
DOUT3
DOUT4
DOUT5
RIN3
RIN2
RIN1
VCC GND
OE
SN65C3238
DB-9
Connect to PC
DCD
RTS
DTR
TXD
RI
CTS
RXD
DSR
GND
1
2
3
4
5
6
7
8
9
Figure 21: RS232 Level Match Circuit
1. The module disables the hardware flow control by default. When hardware flow control is required,
RTS and CTS should be connected to the host. AT command AT+IFC=2,2 is used to enable
hardware flow control. AT command AT+IFC=0,0 is used to disable the hardware flow control. For
more details, please refer to document [1].
2. Rising edge on DTR will let the module exit from the data mode by default. It can be disabled by AT
commands. Refer to document [1] about the command AT&D and AT&V for details.
3. DCD is used as data mode indication. Refer to document [1] about the command AT&C and AT&V
for details.
3.11. USIM Card Interface
The USIM card interface circuitry meets ETSI and IMT-2000 SIM interface requirements. Both 1.8V and
3.0V USIM cards are supported.
Table 12: Pin Definition of the USIM Interface
Pin Name
Pin No.
I/O
Description
Comment
USIM_VDD
14
PO
Power supply for USIM card.
Either 1.8V or 3.0V is supported
by the module automatically.
USIM_DATA
15
IO
Data signal of USIM card.
Pull-up to USIM_VDD with 15k
resistor internally.
NOTES