Analog Devices ADSP-SC58 Series Hardware Reference Manual page 897

ADSP-SC58x EPPI Register Descriptions
Table 18-49: EPPI_CTL Register Fields (Continued)
Bit No.
(Access)
22 PACKEN
(R/W)
21 SKIPEO
(R/W)
20 SKIPEN
(R/W)
19 DMIRR
(R/W)
18:16 DLEN
(R/W)
18–58
Bit Name
Pack/Unpack Enable.
The EPPI_CTL.PACKEN select whether or not packing is enabled (for receive
modes) and unpacking is enabled (for transmit modes). When this bit is set, EPPI
transfer DMA is 32-bits wide. When this bit is cleared and the EPPI_CTL.DLEN is
less than or equal to 16 bits, EPPI transfer DMA is 16-bits wide.
For receive modes, if this bit is set, then the EPPI packs the incoming data into 32-bit
words. If this bit is cleared, then the EPPI does not do any packing.
For transmit modes, if this bit is set, then the EPPI always unpacks the 32-bit data
from DMA. If this bit is not set, the EPPI does not do any unpacking.
Skip Even or Odd.
The EPPI_CTL.SKIPEO bit selects whether even (if set) or odd (if cleared) samples
are skipped if sample skipping is enabled (EPPI_CTL.SKIPEN is set). This feature
only is useful for receive modes.
Skip Enable.
The EPPI_CTL.SKIPEN bit enables skipping alternate samples. This feature only is
useful for receive modes.
Data Mirroring.
The EPPI_CTL.DMIRR field enables mirroring (bit reversing) of the data coming in
or going out on the EPPI data pins.
Pin
Data
------------------------------
15
14
....
1
0
Data Length.
The EPPI_CTL.DLEN bits select the data length for the EPPI. Note that the 20 bits
data length selection is valid only for SMPTE modes (EPPI_CTL.SPLTWRD set).
ADSP-SC58x/ADSP-2158x SHARC+ Processor Hardware Reference
Description/Enumeration
0 Disable
1 Enable
0 Skip Odd Samples
1 Skip Even Samples
0 No Samples Skipping
1 Skip Alternate Samples
PPI Data PPI Data
(DAT_MRR=0) (DAT_MRR=1)
15 0
14 1
.... ....
1 14
0 15
0 No Data Mirroring
1 Data Mirroring