ET-314AC
High Performance GPS Engine Board
2010/4/1
- 4 -
PIN Number(s) Name
Type
Description
Note
1
VCC
P
Main power supply to the engine board.
2,10,30 GND
P
Ground.
3
BOOTSEL
I
Set this pin to high for programming flash.
2
4 RxD0
I
This is the main receive channel for receiving
software commands to the engine board from
SiRFdemo software or from user written
software.
1
5 TxD0
O
This is the main transmits channel for
outputting navigation and measurement data
to user’s navigation software or user written
software. Output TTL level, 0V ~ 2.85V.
6
TxD1
O
Serial output (default null)
7
RxD1
I
Serial input (default null)
1
8
GPIO14
I/O
General purpose I/O
1,3
9,25,26
NC
ET-314AC reserves PIN
11,12,13,14,
15,16,18
GND_A
P
GPS RF Ground.
17.
RF IN
RF
GPS antenna input
19
V_ANT
I
Antenna Bias voltage
20
VCC_RF
O
Supply Antenna Bias voltage (V=VCC)
21
V_BAT
P
Backup battery supply voltage
22
RESET
I
System reset (active low)
23
VDD28OUT
O
Output voltage 2.85V
24
GPIO1
I/O
General purpose I/O
2,3
27
GPIO13
I/O
General purpose I/O
1,3
28
GPIO15 I/O
General purpose I/O
1,3
29
1PPS
O
One pulse per second output.
2,3
<Note>
1. Internal pull-up resistor (100K
Ω
nominal).
2. Internal pull-down resistor (100K
Ω
nominal).
3. Default input at reset.
