CDCE62005: Register 7, bit 27 returns 0

EranR

Part Number: CDCE62005

Hello,

I have a couple of CDCE62005 on a custom board.

For the first few times, reg 7 bit 27 was 1 (according to the datasheet - its a reserved bit and should always be 1) on both CDCE62005.

Now, one of them is 0 (even though I tried to re-program it), the other CDCE62005 is fine.

What could be the reason for that? -All the other registers return value as should, including the rest of reg 7.

Does it have any special meaning? -the datasheet doesn't specify.

Thanks in advance,

over 6 years ago

0 Lane Boyd over 6 years ago

TI__Genius 16845 points

Have you locked the EEPROM on either device yet? Are you able to writes to the device EEPROM?

0 EranR over 6 years ago in reply to Lane Boyd

Intellectual 260 points

No, I have not locked the EEPROM.

The problem happened during RAM read and write (before trying to write the EEPROM).

0 Lane Boyd over 6 years ago in reply to EranR

TI__Genius 16845 points

Thanks for confirming that you did not lock the EEPROM.

Next, please try to write commands to EEPROM (unlocked) and confirm that the EEPROM is programmed correctly.

Kind regards,
Lane

0 Ariel Aviad over 6 years ago in reply to Lane Boyd

Prodigy 80 points

Hi,

we have written this following configuration

reg1       0xEB840320,
reg2     0xEB840301,
reg3      0xEB840302,
reg4      0xEB840303,
reg5       0x6B840314,
reg6       0xFC080A75,
reg7       0x069E0086,
reg8       0x95923D47

after I write this config and I we want to validate everything is the same except

reg8 thats returns

0x15923D47 instead of 0x95923D47

0 Ariel Aviad over 6 years ago in reply to Lane Boyd

Prodigy 80 points

Hi Lane,

In continue of the question.

we have written this following configuration

reg1 0xEB840320,
reg2 0xEB840301,
reg3 0xEB840302,
reg4 0xEB840303,
reg5 0x6B840314,
reg6 0xFC080A75,
reg7 0x069E0086,
reg8 0x95923D47

after I write this config we validate everything and it is the same except

reg8 thats returns

0x15923D47 instead of 0x95923D47
thou just bit 17 is 0 instead of 1

0 Ariel Aviad over 6 years ago in reply to Ariel Aviad

Prodigy 80 points

Sorry bit 27 is 0 instead of 1 not 17

0 Lane Boyd over 6 years ago in reply to Ariel Aviad

TI__Genius 16845 points

Thanks for confirming that you are able to write to the EEPROM.

Please try to write one more configuration to the device and confirm that the registers are reading back correctly. You can use the default configuration; this is simply to confirm the other registers are writing correctly.

Also, check the outputs of the CDCE62005 and confirm that they are correct.

Kind regards,
Lane

0 Ariel Aviad over 6 years ago in reply to Lane Boyd

Prodigy 80 points

Hi Lane,

I have tried other configurations for the other registers and they have worked.

0 Lane Boyd over 6 years ago in reply to Ariel Aviad

TI__Genius 16845 points

Hi Ariel,

Thank you for your efforts confirming that the EEPROM is not locked, and that the device is programming correctly.

R7.27 is a read-only register that is not used in the device operation. Even though you were somehow able to write this bit, it should not have an impact device operation. Your ability to program CDCE62005 successfully confirms this. That being said, it is not recommend to write values to read-only bits/registers.

Kind regards,
Lane

0 Ariel Aviad over 6 years ago in reply to Lane Boyd

Prodigy 80 points

Hi Lane,

Thank you for the help, and for confirmation.

Clock & timing

Clock & timing forum

CDCE62005: Register 7, bit 27 returns 0