Specifications

these pins are used for UART 1. However there is only one UART (UART 0) on any Si100x-based
SNAP device.
UART1
There is only one UART on the RF30x. It is UART 0, though it comes out on the pins normally used
for UART 1.
SPI
SPI uses pins GPIO_4, GPIO_5 and GPIO_6 as MOSI, SCLK, and MISO, respectively. Additionally,
you will need to define a chip select pin for each SPI device. (If you load the RF30x SNAP Engine
with the appropriate Si100x firmware, the SPI interface shifts back to GPIO_12, GPIO_13, and
GPIO_14, as MOSI, SCLK, and MISO, consistent with other SNAP Engines. You will no longer have
access to SPI on GPIOs 4-6 if you do this.)
I
2
C
Two pins can optionally be used for I
2
C: pins 2 and 3 (GPIO_0 and GPIO_1, for SDA and SCL,
respectively). Use external pull-up resistors to VCC. Resistors on the order of 10 KΩ work well.
NOTE – these are not the hardware I
2
C pins. SNAPpy I
2
C is done via software emulation.
PWM
You can configure up to six Pulse Width Modulation (PWM) outputs, assigned to the available GPIO
pins of your choice, except GPIO_16 through GPIO_18. (If you load the RF30x SNAP Engine with
the appropriate Si100x firmware, GPIOs 11-14 can be used for PWM.)
Virtual Machine Speed
RF30x firmware SNAP 2.4 Instructions Per Second (IPS): 3300
Sleep
If using the Si100x firmware on an RF30x SNAP Engine and you need to use a low-power sleep
mode, you should make sure pin 13 (GPIO_11) is high before sleeping. Setting this pin low activates
the external memory, causing it to draw current while the node sleeps. The RF300 includes a crystal to
regulate sleep timings, so you must use only sleep modes 0 and 1. NV Parameter 65 has no effect.
Alternate Radio Trim settings:
NV Parameter 63 is used on the Si100x. The default value is 183 but you can override this by saving a
new value in NV #63. For the definition of the trim value, refer to the Silicon Labs datasheets.
Vendor-specific settings:
NV Parameter 64 is used on the RF30x.
Bit 0x0001 – For the RF30x, the bit should be clear (set to 0). See the Si100x section for details about
the setting.
Encryption
RF30x SNAP Engines do have AES-128 firmware available. The default firmware for the nodes does
not include AES-128 capability, but you can load AES-128-capable firmware into the modules. All
RF30x SNAP Engines have Basic encryption available.
SNAP Reference Manual Document Number 600-0007K Page 175 of 202