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ADIN1110 SPI clarification (Turn around field, SPI Packet clarification)

Hi, colleagues!

While evaluating ADIN1110 we need to clarify:

  1. Pls advise what is the purpose of the turn around (TA) field in the generic SPI protocol reading package? In the documentation, this term occurs exactly once, and clarification is not obvious.
  2. The documentation says that SPI packets should be multiples of four bytes, however, for example, only 55 bits are described in Table 19. Apparently, the exchange will still consist of 64 bits, 32 of which represent a command, and 32 - the response of the chip. Then we must assume that bits 63 to 56 are reserved. Apparently, they need to be set to zero. Is it a correct understanding?
  • Hi Dmitry,

    Apologies for the late reply.

    Regarding your two questions:

    1) The TurnAround field is an 8-SCLK cycle separation between the data you send in the SDI, and when the ADIN1110 starts sending data on the SDO. You can set this TA field to be all 0.

    2) The access to the register map needs to be multiple of 4-bytes, not the SPI frame itself. Rephrasing that, it is the payload of the SPI transaction what needs to be a multiple of 4-bytes. For example:

    -If you look at Table 18, the data you send to the ADIN1110 is 32-bits

    -If you look at Table 19, the data you receive from the ADIN1110 is 32-bits.

    -In table 20, doing a burst write, the data you send to the ADIN1110 is 64-bits (2x4-bytes)

    -In table 21, doing a burst read, the data you receive from the ADIN1110 is 64-bits (2x4-bytes).

    So going back to the transaction in Table 19. the SPI frame is 56 bits long; there are no bits 63 to 56. Bits 55 to 32 is the read command, and bits 31 to 0 (1x4-byte) is the data read back from the ADIN1110.

    I hope this clarifies your queries. Please don't hesitate to ask for more assistance.

    Kind regards,

    Raquel.