V2.0 – Jan-13
User’s Manual
Page 22 of 41
5.4 Description A2100-B Signals
Pin Symbol
Function
Description
1
nRST
Input
Reset input, active low
2
BOOTSEL
Input
Special boot mode – leave open for normal operation;
HIGH – boot loader active; HIGH level:
1.8V
3
N.C.
None Leave
open
4
WAKEUP
Output
Status of digital section, Push-Pull output
Low = OFF, KA (Keep Alive)-only, Hibernate, or Standby mode
High = ON, operational mode
Identical logic to RFPWUP of A1084 on same pin!
5
Vcc
Power Supply
1.7 – 1.9 VDC (power supply)
6
GND
Power Supply
Ground (power supply)
7
GND
Power Supply
Ground (power supply)
8
GPIO6
CTS
SPI CLK
Input
Configuration pin to run in UART mode (10k pull-up to 1.8V, e.g.
to Vcc, pin 5);
leave open for SPI & host port I2C modes
SPI clock pin when module works in SPI mode
9
GPIO7
RTS
SPI CS
Input
Configuration pin for communication mode. 10K to GND for host
port I2C mode; leave open for SPI & UART modes
SPI chip select pin when module works in SPI mode
10
N.C.
None Leave
open
11
N.C.
None Leave
open
12
ANT
Antenna Input
Antenna signal / Z=50 Ohm (antenna input) – must not exceed
30dB gain including cable loss
13
ANT_GND
RF GND
Antenna Ground
14
N.C.
None Leave
open
15
VANT
Antenna Supply
Voltage Input
Power supply input for external active antenna – provide ac-
cording voltage (up to 5.0 VDC) – switched internally
16
TM_GPIO5
Output
Time Mark – 1PPS signal
17
I2C CLK
Output
I2C clock Output to MEMS interface
18
I2C DIO
Input/Output
I2C I/O to MEMS interface
19
ON_OFF
Input
Connect to push-pull output! This is mandatory!
- Set to LOW by default
- Toggle to HIGH and back to LOW
- for first start-up after power on
- to request a fix in SiRFaware
TM
or PTF mode
- to go into or to wake up out of hibernate mode
20
ExtInt
Input
Interrupt input for MEMS interface
( If ExtInt is not going to be used, it is recommended that this pin
be tied directly to ground. Otherwise, a 100K pull-down resistor
to ground should be connected to the ExtInt pin.)
21
TX0
SPI DO
(Host port
I2C_CLK)
Output
Serial output 0, NMEA out if configured for UART
SPI data out pin when module works in SPI mode
Host port I2C clock pin when module works in host port I2C
mode
22
RX0
SPI DI
Input
Serial input 0, NMEA in if configured for UART
SPI data in pin when module works in SPI mode
