Analog Devices ADSP-SC58 Series Hardware Reference Manual page 864

Table 18-12: EPPI Transmit Data Formats (Continued)
Output Data Width
12
14
16
18
Data Transfer Modes
The following sections describe EPPI data transfer modes, including receive or transmit data packing, sign exten-
sion, zero fill, receive or transmit split modes, clock gating, delayed start, and data consistency management.
Data Packing for Receive Modes
For receive modes, if the EPPI_CTL.PACKEN bit =1 and the DMA is 32 bits, the EPPI packs the incoming data
into 32-bit words based on the EPPI_CTL.DLEN and EPPI_CTL.SWAPEN bit settings. When
EPPI_CTL.SWAPEN =0, the EPPI puts the first data in the least significant bits and when EPPI_CTL.SWAPEN
=1, the EPPI puts the first data in the most significant bits. The packing options for the EPPI_CTL.DLEN bits are
as follows.
• When EPPI_CTL.DLEN =8, four 8-bit words can be packed into one 32-bit word.
• When EPPI_CTL.DLEN =16, two 16-bit words can be packed into one 32-bit word.
• For EPPI_CTL.DLEN values that are more than 8 bits but less than 16 bits, two such words are either sign-
extended or zero-filled to 16 bits, and packed into one 32-bit word.
• When EPPI_CTL.DLEN =18, the EPPI sign-extends or zero-fills the 18-bit data to 24 bits and packs four
24-bit words into three 32-bit words.
ADSP-SC58x/ADSP-2158x SHARC+ Processor Hardware Reference
Use Model
DACs
DACs
8-bit luma/chroma pair for NTSC
or HD
16-bit luma/chroma pair for
NTSC or HD
RGB565 LCD
8-bit ADCs
I/Q pair
16-bit ADCs
I/Q pair
RGB666 LCD
Splitting/Packing Options
EPPI_CTL.SPLTEO =1, EPPI_CTL.SUBSPLTODD =0.
EPPI_CTL.SPLTEO =1, EPPI_CTL.SUBSPLTODD =0.
EPPI_CTL.SPLTEO =1, EPPI_CTL.SPLTWRD =1,
EPPI_CTL.SUBSPLTODD =1 if the chroma components (U and V)
come in separate DMA words.
EPPI_CTL.SPLTEO =1, EPPI_CTL.SPLTWRD =0,
EPPI_CTL.SUBSPLTODD =1 if the chroma components (U and V)
come in separate DMA words.
No splitting possible.
EPPI_CTL.RGBFMTEN =1. Takes RGB888 data from the memory
and drops the LSBs from each component to drive out RGB565 data.
EPPI_CTL.SPLTEO =1, EPPI_CTL.SPLTWRD =1,
EPPI_CTL.SUBSPLTODD = 0
EPPI_CTL.SPLTEO =1, EPPI_CTL.SPLTWRD =0,
EPPI_CTL.SUBSPLTODD =1
No splitting possible.
EPPI_CTL.RGBFMTEN =1. Takes RGB888 data from the memory
and drops the 2 LSBs from each component to drive out RGB666 data.
EPPI Operating Modes
18–25