Specifications

Reserved Hardware
Timers
On the Si100x, SNAP uses Timer 1 and Timer 2 internally.
Timer 2 provides the 1 millisecond “heartbeat.” You should not do anything that makes explicit use of
that timer.
Timer 1 is used to set the UART baud rate. If you are not using a serial connection, you can use Timer
1 for your own purposes. (The real-time clock is also available to you. Initialization of the real-time
clock is cumbersome, but can be automated by executing a brief timed sleep.)
Timers 0 and 3 are available for user interaction. See the manufacturer’s documentation for details in
using these.
Advanced SNAP Hardware Assumptions
If you are designing your own circuitry using the Si100x, keep these assumptions in mind:
• The radio shutdown pin is tied to P0.7.
• The radio interrupt pin is tied to P0.1.
• Tie GPIO_1 to receive on the RF multiplexer.
• Tie GPIO_2 to transmit on the RF multiplexer.
SNAP Reference Manual Document Number 600-0007K Page 173 of 202