Specifications

Product Technical Specification & Customer Design Guidelines
42 Proprietary and Confidential - Specifications subject to change 2400058
4.5.1 UART1 pin descriptions
Tabl e 4- 8 describes the UART1 interface pins.
See Digital I/O electrical information on page 39 for 1V8 voltage characteristics
and reset state definitions.
4.5.2 Interface implementation
See Reference schematic on page 40 for an implementation of the UART1
interface.
4.6 SIM interface
The AirPrime SL808X Embedded Module includes a 4-wire USIM interface that
allows a SIM to be directly connected. Ta bl e 4-9 describes the purpose and
features of this interface.
Table 4-8: Serial port UART1 interface
Pin Signal I/O
type
Reset
state
a
Description Direction
wrt host
Notes
45 UART1_RXD 1V8 High speed
UART - Transmit
data
Input • Digital pin input, internal
Pull Down
• UART1 serial data transmit
line (modem output)
46 UART1_TXD 1V8 High speed
UART - Receive
data
Output • UART1 serial data receive
line (modem input)
47 UART1_RTS_
N
1V8 High speed
UART - Clear to
send
Output
48 UART1_CTS_
N
1V8 High speed
UART - Request
to send
Input
a. See Table 4-4 on page 40 for state definitions.
Table 4-9: USIM interface features
Feature Details
Purpose • Communicate with USIM socket on host device
• Supports regular and embedded SIMs
Implementation • Four-wire interface
• Voltage levels comply with 3GPP standards
Power • 1.8 V (3G) or 3.0 V (2G) operation. Compliant with GSM
11.11 recommendations concerning SIM functions.
• Host must keep current draw ≤10mA