Texas Instruments CC3235 SimpleLink Series - RFIFOCTL Register; RFIFOCTL Register Field Descriptions

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SWRU543–January 2019
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Inter-Integrated Sound (I2S) Multichannel Audio Serial Port
12.5.4 RFIFOCTL Register (Offset = 18h) [reset = 1004h]
RFIFOCTL is shown in Figure 12-7 and described in Table 12-9.
Return to Summary Table.
The RNUMEVT and RNUMDMA values must be set before enabling the Read FIFO. If the Read FIFO is
to be enabled, it must be enabled before taking the McASP out of reset.
Figure 12-7. RFIFOCTL Register
31 30 29 28 27 26 25 24
RESERVED
R-0h
23 22 21 20 19 18 17 16
RESERVED RENA
R-0h R/W-0h
15 14 13 12 11 10 9 8
RNUMEVT
R/W-10h
7 6 5 4 3 2 1 0
RNUMDMA
R/W-4h
LEGEND: R/W = Read/Write; R = Read only; W1toCl = Write 1 to clear bit; -n = value after reset
Table 12-9. RFIFOCTL Register Field Descriptions
Bit Field Type Reset Description
31-17 RESERVED R 0h
Reserved. The reserved bit location always returns the default value.
A value written to this field has no effect. If writing to this field,
always write the default value for future device compatibility.
16 RENA R/W 0h
Read FIFO enable bit.
0h = Read FIFO is disabled. The RLVL bit in the Read FIFO status
register (RFIFOSTS) is reset to 0 and pointers are initialized, that is,
the Read FIFO is “flushed.”
1h = Read FIFO is enabled. If Read FIFO is to be enabled, it must
be enabled before taking McASP out of reset.
15-8 RNUMEVT R/W 10h
Read word count per DMA event (32-bit). When the Read FIFO has
space for at least RNUMEVT words of data, then an AREVT (receive
DMA event) is generated to the host/DMA controller. This value
should be set to a nonzero integer multiple of the number of
serializers enabled as receivers. This value must be set before
enabling the Read FIFO.
0h = 0 words
1h = 1 word
2h = 2 words
3h - 40h = 3 to 16 words
41h - FFh = Reserved
7-0 RNUMDMA R/W 4h
Read word count per transfer (32-bit words). Upon a receive DMA
event from the McASP, RNUMDMA words are transferred from the
Read FIFO to the McASP. This value must equal the number of
McASP serializers used as receivers. This value must be set before
enabling the Read FIFO.
0h = 0 words
1h = 1 word
2h = 2 words
3h - 10h = 3 to 16 words
11h - FFh = Reserved