Registers
1188
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Multichannel Audio Serial Port (McASP)
24.1.45 Write FIFO Control Register (WFIFOCTL)
The Write FIFO control register (WFIFOCTL) is shown in
and described in
.
NOTE:
The WNUMEVT and WNUMDMA values must be set prior to enabling the Write FIFO.
If the Write FIFO is to be enabled, it must be enabled prior to taking the McASP out of reset.
Figure 24-78. Write FIFO Control Register (WFIFOCTL)
31
17
16
Reserved
WENA
R-0
R/W-0
15
8
7
0
WNUMEVT
WNUMDMA
R/W-10h
R/W-4h
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
Table 24-47. Write FIFO Control Register (WFIFOCTL) Field Descriptions
Bit
Field
Value
Description
31-17
Reserved
0
Reserved
16
WENA
Write FIFO enable bit.
0
Write FIFO is disabled. The WLVL field in the Write FIFO status register (WFIFOSTS) is reset to 0
and pointers are initialized, that is, the Write FIFO is “flushed.”
1
Write FIFO is enabled. If Write FIFO is to be enabled, it must be enabled prior to taking McASP
out of reset.
15-8
WNUMEVT
0-FFh
Write word count per DMA event (32-bit). When the Write FIFO has space for at least WNUMEVT
words of data, then an AXEVT (transmit DMA event) is generated to the host/DMA controller. This
value should be set to a non-zero integer multiple of the number of serializers enabled as
transmitters. This value must be set prior to enabling the Write FIFO.
0
0 words
1h
1 word
2h
2 words
3h-40h
3 to 64 words
41h-FFh
Reserved
7-0
WNUMDMA
0-FFh
Write word count per transfer (32-bit words). Upon a transmit DMA event from the McASP,
WNUMDMA words are transferred from the Write FIFO to the McASP. This value must equal the
number of McASP serializers (not the number of channels) used as transmitters. This value must
be set prior to enabling the Write FIFO.
0
0 words
1h
1 word
2h
2 words
3h-10h
3-16 words
11h-FFh
Reserved