A N 6 3 3
16
Rev. 0.7
7.2.2. GPIO Checking Method
Any GPIO can be configured for monitoring the CTS. GPIOs can be configured to go either high or low when the
chip has completed the command. The function of the GPIOs can be changed by the GPIO_PIN_CFG command.
By default, GPIO1 is set as "High when command completed, low otherwise" after Power On Reset. Therefore, this
pin can be used for monitoring the CTS right after Power On Reset to know when the chip is ready to boot up.
7.2.3. NIRQ Interrupt Checking Method
The radio asserts the CHIP_READY interrupt flag if a command is completed. The interrupt flag can be monitored
by either the GET_CHIP_STATUS or the GET_INT_STATUS command. Apart from monitoring the interrupt flags,
the radio may pull down the NIRQ pin if this feature is enabled. If a new command is sent while the CTS is
asserted, then the radio ignores the new command. The Si446x can generate an interrupt to communicate this
error to the MCU by the CMD_ERROR interrupt flag in the CHIP_STATUS group. The interrupt flag has to be read
(by issuing a GET_CHIP_STATUS or GET_INTERRUPT_STATUS command) to clear the pending interrupt and
release the NIRQ pin. No other action is needed to reset the command buffer of the radio, but, after a
CMD_ERROR, the host MCU should repeat the new command after the radio has processed the previous one.
All the commands that are sent to the radio have the same structure. After pulling down the NSEL pin of the radio,
the command ID should be sent first. The commands may have up to 15 input parameters.
Figure 7. Host MCU Sends Command to Radio
7.3. Getting Response to a Command from the Radio
Reading from the radio requires several steps to be followed. The host MCU should send a command with the
address it requests to read. The radio holds the CTS while it retrieves the requested information. Once the CTS is
set (0xFF), the host MCU can read the answer from the radio.
Figure 8. Read Procedure
If the CTS is polled on the GPIOs, or the radio is configured to provide interrupt if the answer is available, then the
response can be read out from the radio with the following SPI transaction.
Send Command
Read CTS
Retrieve
Response
CTS Value
Not
0xFF
0xFF
Содержание EZRADIOPRO Si4060
Страница 24: ...AN633 24 Rev 0 7 Figure 20 Supply Current versus Time Diagram from Shutdown to RX State...
Страница 67: ...AN633 Rev 0 7 67 Figure 48 Variable Length Packet Reception Flowchart...
Страница 69: ...AN633 Rev 0 7 69 Figure 50 Packet Matching Reception Flowchart...
Страница 73: ...AN633 Rev 0 7 73 Figure 54 Packet Reception with Automatic RX Hopping Flowchart...
Страница 75: ...AN633 Rev 0 7 75 Figure 56 Packet Reception with Manual Rx Hopping...
Страница 80: ...AN633 80 Rev 0 7 Figure 62 Long Packet Transmission Workflow...
Страница 81: ...AN633 Rev 0 7 81 Figure 63 Long Packet RX Flowchart...
