Texas Instruments TMS320 2806 Series, Technical Reference Manual

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12.5.2.10 SPI FIFO Receive (SPIFFRX) Register (Offset = Bh) [reset = 201Fh]
SPIFFRX contains both control and status bits related to the input FIFO buffer. This includes FIFO reset control,
FIFO interrupt level control, FIFO level status, as well as FIFO interrupt enable and clear bits.
Figure 12-22. SPI FIFO Receive (SPIFFRX) Register
15 14 13 12 11 10 9 8
RXFFOVF RXFFOVFCLR RXFIFORESET RXFFST
R-0h W-0h R/W-1h R-0h
7 6 5 4 3 2 1 0
RXFFINT RXFFINTCLR RXFFIENA RXFFIL
R-0h W-0h R/W-0h R/W-1Fh
Table 12-18. SPI FIFO Receive (SPIFFRX) Register Field Descriptions
Bit Field Type Reset Description
15 RXFFOVF R 0h Receive FIFO Overflow Flag
Reset type: SYSRSn
0h (R/W) = Receive FIFO has not overflowed. This is a read-only bit.
1h (R/W) = Receive FIFO has overflowed, read-only bit. More than 4
words have been received in to the FIFO, and the first received word
is lost.
14 RXFFOVFCLR W 0h Receive FIFO Overflow Clear
Reset type: SYSRSn
0h (R/W) = Write 0 does not affect RXFFOVF flag bit, Bit reads back
a zero.
1h (R/W) = Write 1 to clear SPIFFRX[RXFFOVF].
13 RXFIFORESET R/W 1h Receive FIFO Reset
Reset type: SYSRSn
0h (R/W) = Write 0 to reset the FIFO pointer to zero, and hold in
reset.
1h (R/W) = Re-enable receive FIFO operation.
12-8 RXFFST R 0h Receive FIFO Status
Reset type: SYSRSn
0h (R/W) = Receive FIFO is empty.
1h (R/W) = Receive FIFO has 1 word.
2h (R/W) = Receive FIFO has 2 words.
3h (R/W) = Receive FIFO has 3 words.
4h (R/W) = Receive FIFO has 4 words, which is the maximum.
1Fh (R/W) = Reserved.
7 RXFFINT R 0h Receive FIFO Interrupt Flag
Reset type: SYSRSn
0h (R/W) = RXFIFO interrupt has not occurred. This is a read-only
bit.
1h (R/W) = RXFIFO interrupt has occurred. This is a read-only bit.
6 RXFFINTCLR W 0h Receive FIFO Interrupt Clear
Reset type: SYSRSn
0h (R/W) = Write 0 has no effect on RXFIFINT flag bit, Bit reads back
a zero.
1h (R/W) = Write 1 to clear SPIFFRX[RXFFINT] flag
Serial Peripheral Interface (SPI) www.ti.com
794 TMS320x2806x Microcontrollers SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
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