What is the maximum resolution that ADV7611 can output using 8bit bus? I can't seem to find it. Thank you
Can 720p be supported in an 8bit mode?
The pixel bus of the ADV7611 can support up to 1080p60 (pixel output clock of 148MHz).
This is using the full pixel bus in a 16 to 24bit mode.
The ADV7611 supports two 8-bit modes.
- In a standard SDR or (psuedo DDR), outputs up to and including 480p/576p are supported.
- In a DDR mode a pixel clock of up to 75 Mhz is supported so outputs up to 720p60/1080i60 can be supported.
Yes - 720p can be supported in an 8bit DDR configuration.
Thank you very much..
I have been trying to determine if the ADV7611 can support our desired video input (1080p, 30fps) while using the 8-Bit SDR BT.656 output pixel format.
According to my estimate, the bandwidth required for 1080p30 video would be as follows for the 8-Bit SDR mode:
Pixel Clock Rate = (Frame Length) X (Frame Width) X (30 frames per second) X (1.35 factor for overhead) X (2 clock cycles per pixel) = (1920)*(1080)*(30)*(1.35)*(2) = 167.9616 MHz
According to the ADV7611 datasheet, the maximum LLC (pixel clock) rate is 165MHz. Since this is so close to my estimate, I wanted confirmation that the HDMI receiver can or cannot support 1080p30 video output with the 8-Bit SDR interface. It is possible that I overestimated the bandwidth slightly since I am simply using a 35% approximation.
Unfortunately, 1080p30 is not supported in 8bit SDR mode.
Customer would like to use BT.656 8-bit 4:2:2 SDR mode for 720p.
So, “98 03 00 ; 8 bit 656” is described in http://ez.analog.com/thread/8553.
Also, 0x00 is 8-bit SDR ITU-656 mode and 0x20 is 8-bit 4:2:2 DDR mode in SW manual.
By the way, my colleague said the data should be changed to 0x00 to 0x20. He had experience about this.
So, we tested that the LLC is abnormal waveform with 0x00 but when LLC is 148.5Mhz when data is 0x20.
However, how to set the data when BT.656 8-bit 4:2:2 SDR mode for 720p? Please clarify it
Unfortunately 720p is not supported in BT656 8bit mode. A 16/20/24 bit mode or DDR mode needs to be used.
BT656 8bit DDR mode is possible for 720p? Please let me know.
On my understanding, this LLC clock is required to 74.25Mhz on 720p of BT656 8bit DDR mode.
"DDR mode is only supported only up to 50 MHz (an equivalent to data rate clocked 100 MHz clock in SDR mode)" is described in page 12 of web datasheet.
You were saying “In a DDR mode a pixel clock of up to 75 Mhz is supported so outputs up to 720p60/1080i60 can be supported.” in previouse post’s answer.
Would you please clarify it?
Also, could you provide script file for this configuration in EVAL-ADV7611EB1Z(bothADV7611 and ADV7511)?
After checking with other engineers here, I found that 720p60 can be used in 8-bit 656 mode.
This evalaution work was carried out after the main evaluation.
For correct operation it is important that the PCB traces are keep short and well routed for best performance.
Sorry for any inconvenience,
Could you provide the script file for 720p60 with 8bit BT.656 in EVAL-ADV7611EB1Z(both ADV7611 and ADV7511)?
If we can not acheive the test with EVAL-ADV7611EB1Z due to ADV7511 limitation, please share just ADV7611's script file.
The standard evaluation board is not supplied with this particular mode and this might be source of consfusion.
To make things straight:
- 720p60 8-bit is supported
- It is documented on page 27 in User Guide UG-180 (page 27, DLL Settings for 656, 8-/10-/12-Bit Modes)
- It requires precise DLL adjustment, proper termination and impedance matching due to high clock freq.
As I said - we do not supply script for that, but normal script for the eval board can be reworked into 8-bit usnig the writes provided in the UG-180.
I hope this helps & clarify things.
After reading this theme and a couple of others with similar questions I still can't understand what resolutions are supported by ADV7611 in 8-bit SDR and 8-bit DDR. There is just too much controversion in the answers. It is still not clear about 75MHz DDR while datasheet specifies that "DDR mode is only supported only up to 50 MHz".
1) So, what resolutions and frame rates are supported by 8-bit SDR?
720p30? 720i30? 720p60? 720i60? 1080p30? 1080i30? 1080p60? 1080i60?
2) And what resolutions are supported on 8-bit DDR?
3) Also, what resolutions are supported on 12-bit SDR?
I would be very thankful for a clarification.
The limiting factors on all resolutions is the maximum SDR clock rate of 165MHz and maximum DDR clock rate of 50MHz and required pixel bus width
1) 8-bit SDR assuming RGB or YCbCr 444 or 422 output format, OP_FORMAT_SEL = 0x00
Yes to 720p30, 720i30, 720p60, 1080p30, 1080i30
No to 1080p60, clock rate would be 297 MHz
2) 8-bit DDR, assuming RGB or YCbCr 422 output format, OP_FORMAT_SEL = 0x20
Yes to 720p30, 720i30, 720p60, 1080p30, 1080i30, ddr clock rates are less then 37MHz
No to 1080p60, ddr clock rate would be 148.5MHz
3) 12-bit SDR assuming YCbCr 422 output format, OP_FORMAT_SEL = 0x0A
Thank you for the answer.
Good to hear that 1080p30 can work on 8-bit SDR (as that is the only thing available on my module).
Are there any underwater stones with 1080p30 on 8-bit SDR or should it just work?
I would use separate syncs, not embedded sync like BT.656 specifics. 1080p30 8-bit SDR would have a clock rate of 148Mhz.
The best bet is to try this out on the ADV7612-7511 evaluation board.
Got it, I will order the EVAL-ADV7612-7511P board and test it. Thanks!
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