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Rev 0.4
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4.2.4. Using Fast Response Registers
There are several types of status information that can be read out from the radio faster. The FRR_CTL_x_MODE
(where x can be A, B, C or D) properties define what status information is assigned to a given fast response
register (FRR). The actual value of the registers can be read by pulling down the NSEL pin, issuing the proper
command ID, and providing an additional eight clock pulses on the SCLK pin. During these clock pulses, the radio
provides the value of the addressed FRR. The NSEL pin has to be pulled high after finishing the register read.
Figure 13. Reading a Single Fast Response Register
It is also possible to read out multiple FRRs in a single SPI transaction. The NSEL pin has to be pulled low, and
one of the FRRs has to be addressed with the proper command ID. Providing an additional 8 x N clock cycles will
clock out an additional N number of FRRs. After the fourth byte is read, the radio will provide the value of the
registers in a circular manner. The reading stops by pulling the NSEL pin high.
Figure 14. Reading More Fast Response Registers in a Single SPI Transaction
Note:
If the pending interrupt status register is read through the FRR, the NIRQ pin does not go back to high. The pending
interrupt registers have to be read by a Get response to a command sequence in order to release the NIRQ pin.
Содержание Si4455 Series
Страница 8: ...AN692 8 Rev 0 4 Figure 6 Device Configuration Options ...
Страница 22: ...AN692 22 Rev 0 4 Figure 21 Supply Current versus Time Diagram from Shutdown to RX State ...
Страница 23: ...AN692 Rev 0 4 23 4 4 Radio Chip Waking Up Figure 22 Radio Wake Up Process ...
Страница 25: ...AN692 Rev 0 4 25 4 5 EZConfig and Configuration Options Figure 23 Radio RF Initialization Process ...
Страница 35: ...AN692 Rev 0 4 35 Figure 32 Transmission Flowchart ...
Страница 39: ...AN692 Rev 0 4 39 Figure 33 Reception Flowchart ...
Страница 41: ...AN692 Rev 0 4 41 Figure 34 Bidirectional Variable Packet Example Project Flowchart ...
Страница 47: ...AN692 Rev 0 4 47 Figure 41 Long Packet Transmission Flowchart ...
Страница 48: ...AN692 48 Rev 0 4 Figure 42 Long Packet RX Flowchart ...
