SI4322-A1-FTR Silicon Laboratories Inc, SI4322-A1-FTR Datasheet - Page 29

• Manufacturer Part Number: SI4322-A1-FTR
• Manufacturer: Silicon Laboratories Inc

Specifications of SI4322-A1-FTR

• Lead Free Status / Rohs Status: Supplier Unconfirmed

7. FIFO Buffered Data Read
In this operating mode, incoming data are clocked into a 64-bit FIFO buffer. The receiver starts to fill up the FIFO
when the Valid Data Indicator (VDI) bit and/or the synchron word recognition circuit indicates potentially real
incoming data. This prevents the FIFO from being filled with noise and overloading the external microcontroller.
For further details see "5.5. Receiver Setting Command" on page 18 and "5.14. FIFO Settings Command" on page
25.
7.1. Polling Mode
The nFFS signal selects the buffer directly and its content could be clocked out through pin SDO by SCK. Set the
FIFO IT level to 1. In this case, as long as FFIT indicates received bits in the FIFO, the controller may continue to
take the bits away. When FFIT goes low, no more bits need to be taken. An SPI read command is also available.
7.2. Interrupt Controlled Mode
The user can define the FIFO level (the number of received bits) which will generate the nFFIT when exceeded.
The status bits report the changed FIFO status in this case.
7.3. FIFO Read Example with FFIT Polling
Note: During FIFO access f
of the clock signal is not 50% the shorter period of the clock pulse should be at least 2/f
SCK
cannot be higher than f
nSEL
SCK
SDI
nFFS *
SDO
FFIT
FIFO OUT
0
ref
FO+1
/4, where f
1
FIFO read out
Rev. 1.2
FO+2
2
FO+3
ref
3
NOTE:
*nFFS selects FIFO read mode
is the crystal oscillator frequency. When the duty-cycle
FO+4
4
ref
.
Si4322
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