Altera DisplayPort MegaCore Function User Manual
Page 39
Figure 5-3: DisplayPort Sink Functional Block Diagram
Video Output
(rxN_video_out)
20-Bit (Dual Symbol)
or 40-Bit (Quad Symbol)
Data from Transceiver
(rx_xcvr_interface)
Bidirectional AUX Data (rx_aux)
AUX Debug Stream (rx_aux_debug)
Avalon-MM (rx_mgmt)
AUX
Controller
HPD
Controller Registers
De-Scrambler
DP2ST
Gearbox
SS
Decoder
IRQ
Control
VB-ID
Decoder
MSA
Decoder
8B/10B
Aligner
DCFIFO
DCFIFO
Steering
Secondary
Stream (rxN_ss)
HPD
rx_ss_clk
clk
rxN_vid_clk
aux_clk
Legend
Deskew
The device transceiver sends 20-bit (dual symbol) or 40-bit (quad symbol) parallel DisplayPort data to the
sink. Each data lane is clocked in to the IP core by its own respective clock output from the transceiver.
Inside the sink, the four independent clock domains are synchronized to the lane 0 clock. Then, the IP
core performs the following actions:
1. The IP core aligns the data stream and performs 8B/10B decoding.
2. The IP core deskews the data and then descrambles it.
3. The IP core splits the unscrambled data stream into parallel paths.
a. The SS decoder block performs secondary stream decoding, which the core transfers into the
rx_ss_clk
domain through a DCFIFO.
b. The main data path extracts all pixel data from the incoming stream. Then, the gearbox block
resamples the pixel data into the current bit-per-pixel data width. Next, the IP core crosses the pixel
data into the
rxN_vid_clk
domain through a DCFIFO. Finally, the IP core steers the data into a
single, dual, or quad pixel data stream.
c. MSA decode path.
d. Video decode path.
You configure the sink to output the video data as a proprietary data stream. You specify the output pixel
data width at 6, 8, 10, 12, or 16 bpc. This format can interface with downstream Altera Video and Image
Processing (VIP) Suite components.
The AUX controller can operate in an autonomous mode in which the sink controls all AUX channel
activity without an external embedded controller. The IP core outputs an AUX debugging stream so that
you can inspect the activity on the AUX channel in real time.
UG-01131
2015.05.04
Sink Functional Description
5-3
DisplayPort Sink
Altera Corporation