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CGMS-A assignments of ADV7392.

Question asked by Tamu on Mar 4, 2014
Latest reply on Mar 14, 2014 by PaulS



I have a question about CGMS-A assignments of ADV7392.


There is a description about "CGMS CRC FUNCTIONALITY" on datasheet page.74 as follows:
"If SD CGMS CRC (Subaddress 0x99, Bit 4) or ED/HD CGMS CRC (Subaddress 0x32, Bit 7) is enabled,
the upper six CGMS data bits (C19 to C14) that comprise the 6-bit CRC check sequence are automatically calculated on the ADV739x.
This calculation is based on the lower 14 bits (C13 to C0) of the data in the CGMS data registers,
and the result is output with the remaining 14 bits to form the complete 20 bits of the CGMS data."


If SD CGMS CRC is enabled, I think the CGMS CRC is automatically calculated and updated to six CGMS data bits (C19 to C14).
But I don't know how we should set to other CGMS bits (C13 to C0).
In EIAJ CPR-1204 specification, the CGMS data has WORD0(2bit), WORD1(4bit) and WORD2(8bit).

Could you tell me which WORD should be assigned to the registers?
Example 1:
WORD0(2bit):C13 to C12
WORD1(4bit):C11 to C8
WORD2(8bit):C7 to C0

Example 2:
WORD0(2bit):C0 to C1
WORD1(4bit):C2 to C5
WORD2(8bit):C6 to C13


Which is correct?
Also, should we assign the registers with "MSB first" or "LSB first"?


Thank you.

Best regards.