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CDCE6214: Mode selection and defaults

Part Number: CDCE6214

Hello TI,

After spending too many hours attempting to decipher the cdce6214 datasheet (snas811), please assist with the following:

1) Apparently, HW_SW_CTRL decides whether the device enters Pin Mode or not. If so, why does snas811 Table 18 have "L/H" for this entry? Should this not be "L" ? Should snas811 Table 18 not perhaps look more like this:

Should the HW_SW_CTRL column not perhaps move left in this Table to indicate its role in mode selection?

2) Is Fall-back mode determined only by HW_SW_CTRL (as Table 20 might imply), or by the combination of HW_SW_CTRL and REFSEL (both "M", according to Table 18)?

3) Does REFSEL = M have any other role other than possibly in conjunction with HW_SW_CTRL = M? With other words, what is the effect of the following:

HW_SW_CTRL = L and REFSEL = M

HW_SW_CTRL = H and REFSEL = M

HW_SW_CTRL = M and REFSEL = L

HW_SW_CTRL = M and REFSEL = H

4) snau247b has

0x1000 as default for register R0 and

0xA020 as default for R15 and

0x0000 as default for R16,

for example (there are others). However, snas811 has:

Is there a discrepancy, perhaps? If so, which is correct?

5) OUT0 can seemingly be sourced from ahead of the "x2" doubler and "R div" divider blocks, but this is not apparent in snas811 Figure 23. Would it be possible to show this option?

Thanks!

  • Hello Bernhard,

    1. the Mode can be programmed via register setting and can be stored in either of the 2 EEPROM pages that the device has. The fallback mode is there, in case both EEPROM pages are programmed to pin mode where you don't have I2C interface.

    So, table 20 is correct, because both EEPROM pages can be in either pin mode or serial interface mode. And you can select the input source.

    2. Fallback mode is defined by both REFSEL and HW_SW_CTRL at M.

    3. No.

    4. I need to look into this.

    5. I agree, that picture could be more clear on that the outputs of the doubler and divider block go on a bus. Please see the GUI for clarification.

    I will enter a support ticket that this figure gets a refresh in the next datasheet update.

    regards,

    Julian

  • Hello Bernhard,

    I wanted to come back on point no4. Datasheet is correct there was an error creating that register map document where the defaults settings did got scrambled up in the 'b' version of the register map (snau247b).

    We will update this. Thanks for highlighting.

    Regards,

    Julian

  • Hello Julian,

    Are you sure that the datasheet default registers are correct? Does 0x7652 make sense for R1 with HW_SW_CTRL = 1? Would this not be 0x7654 as well, for example?

  • Hi Bernhard,

    yes I am sure that the datasheet is correct. EEPROM page 1 has a slightly different default programming vs page 0. You can reprogram these values to the setting that you need in your application.

    Regards,

    Julian