2988 - [LatticeECP3]: Can Lattice High Definition Multimedia Interface/ Digital Visual Interface (HDMI/DVI) reference designs-RD1097 support more resolutions?
Yes. Some settings of Serializer-Deserializer (SerDes) are adjusted through Serial Communication Interface (SCI) to support more resolutions low up to 800x600@60Hz.
"10B only" mode is used in SERDES for our High Definition Multimedia Interface/ Digital Visual Interface (HDMI/DVI) reference designs. With testing, it has been proved that low bit rates(such as 252Mbps for 640x480@60Hz, etc.) are not supported. The standard resolutions listed in RD1097 have been validated. In theory, all resolutions with bit rate in the range from 742.5Mbps(1280x720@60Hz/etc.) to 1.62Gbps(1600x1200@60Hz) are supported.
With the following information, if the user adjust SerDes registers as per item #1, then the user get test results as per item #3. The detail description of SERDES frequency settings is listed in item #2.
1. Related registers
a) CH_10[2:0] (address 0x410/ 0x450/ 0x490/ 0x4D0)
b) QD_0D[2:0] (address 0x50D).
c) The values and the related descriptions:
3’b000 -> HIGH
3’b010 -> MEDHIGH
3’b100 -> MED
3’b101 -> MEDLOW
3’b110 -> LOW
2. The frequency settings and the related SERDES frequency ranges
a) LOWLOW: 150 ~ 230Mbps,
b) LOW : 230 ~ 450 Mbps,
c) MEDLOW : 450 ~ 900 Mbps,
d) MED : 0.9 ~ 1.8 Gbps,
e) MEDHIGH: 1.8 ~ 2.55 Gbps,
f) HIGH : 2.55 ~ 3.2Gbps.
3. The test result based on HDMI/DVI design : RD 1097,
Lattice Video Protocol Board Rev C with LatticeECP3-95EA, HDMI MEZZANINE card Rev B
Frequency settings and the supported video frequency ranges:
a) MEDHIGH : 0.65 ~ 1.62 Gbps ( 1024x768@60Hz ~ 1600x1200@60Hz )
b) MED : 0.4 ~ 1.35 Gbps ( 800x600@60Hz ~ 1280x1024@75Hz )
c) MEDLOW : 0.4 ~ 0.65 Gbps ( 800x600@60Hz ~ 1024x768@60Hz )