Hi,

The table 27 and table 28 on UG-1176.pdf shows as follows:
0x80 Gain on Cb channel = 0 dB
0x00 Gain on Cb channel = −42 dB
0xFF Gain on Cb channel = +6 dB

It doesn't seem that the decibel value(db) is proportional to the register value.
So we don't understand the relationship between them. When we set values except 0x80, 0x00 and 0xFF to the registers, then we don't know how much saturation effect can be seen.

Could you provide us the relationship between the decibel value(db) and the register value including median value?
It's also okey something like a graph which we can understand the relationship.

Thank you!
Best regards.
Tamu

• Hi,

Thank you!
Best regards.
Tamu

• Hi Tamu San,

When we set values except 0x80, 0x00 and 0xFF to the registers, then we don't know how much saturation effect can be seen ?

"0xE3 and 0xE4" registers would effectively increase or decrease the gain according to the register value", so depending on that saturation effect will vary.

Please note that As per expert comment  "Design confirmed that the chroma gain control does not apply to SECAM. It only applies to QAM standard like NTSC and PAL. The gain in the SECAM signal decoding is a function of the FM demodulator and is fixed. However customers can adjust the SECAM color levels by adjusting the Cb/Cr saturation controls (Reg 0xE3 and 0xE4). This would effectively allow them to increase or decrease the SECAM gain.

Note:  Saturation is the amount of color present. For example, a lightly saturated red looks pink, while a fully saturated red looks like the color of a red crayon. Saturation does not mean the brightness of the color, just how much pigment is used to make the color. The less pigment, the less saturated the color is, effectively adding white to the pure color.

Thanks,

Poornima

• Hi Poornima san,

But your comment is not what I want to know.
Could you read my questions again?
And please refer attached file "SD_SAT_Cb_SD_SAT_Cr_details.xlsx".
I summarized my questions to attached file.

Thank you!
Best regards.
Tamu

XLSX

• Hi Tamu San,

As i said already "These(0xE3,0XE4) registers would effectively increase or decrease the gain according to the register value", So customers only need to check the relationship between gain(db) against their register value.

Please note that, we don't have any details other than what design support files manuals specifies.

Thanks,

Poornima

• Hi Poornima san,

Of course, I think the customer should check the effect of the (0xE3,0XE4) registers on their board.
But they want to know the more details as an index of their evaluation.

I understand you don't have more details other than the documents.
Even if you don't have all saturation values(dB) for all of the settings (from 0x00 to 0xFF),
could you provide any useful information as an index for their evaluation?
It's okey something like a graph, etc.