SI4460-C2A-GM Datasheet, PDF (22/53 Pages) Silicon Laboratories – HIGH-PERFORMANCE, LOW-CURRENT TRANSCEIVER

Si4463/61/60-C
3.4. Application Programming Interface (API)
An application programming interface (API), which the host MCU will communicate with, is embedded inside the
device. The API is divided into two sections, commands and properties. The commands are used to control the
chip and retrieve its status. The properties are general configurations which will change infrequently. The API
descriptions can be found on the Silicon Labs website.
3.5. Interrupts
The Si446x is capable of generating an interrupt signal when certain events occur. The chip notifies the
microcontroller that an interrupt event has occurred by setting the nIRQ output pin LOW = 0. This interrupt signal
will be generated when any one (or more) of the interrupt events (corresponding to the Interrupt Status bits) occur.
The nIRQ pin will remain low until the microcontroller reads the Interrupt Status Registers. The nIRQ output signal
will then be reset until the next change in status is detected.
The interrupts sources are grouped into three groups: packet handler, chip status, and modem. The individual
interrupts in these groups can be enabled/disabled in the interrupt property registers. An interrupt must be enabled
for it to trigger an event on the nIRQ pin. The interrupt group must be enabled as well as the individual interrupts in
API properties described in the API documentation.
Once an interrupt event occurs and the nIRQ pin is low there are two ways to read and clear the interrupts. All of
the interrupts may be read and cleared in the “GET_INT_STATUS” API command. By default all interrupts will be
cleared once read. If only specific interrupts want to be read in the fastest possible method the individual interrupt
groups (Packet Handler, Chip Status, Modem) may be read and cleared by the “GET_MODEM_STATUS”,
“GET_PH_STATUS” (packet handler), and “GET_CHIP_STATUS” API commands.
The instantaneous status of a specific function maybe read if the specific interrupt is enabled or disabled. The
status results are provided after the interrupts and can be read with the same commands as the interrupts. The
status bits will give the current state of the function whether the interrupt is enabled or not.
The fast response registers can also give information about the interrupt groups but reading the fast response
registers will not clear the interrupt and reset the nIRQ pin.
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