Plug-In Spi Register Controller - Analog Devices EVAL-ADMV8052 User Manual

UG-1951

PLUG-IN SPI REGISTER CONTROLLER

The ADMV8052 plug-in utilizes an SPI register controller to
communicate with the ADMV8052. When using the
ADMV8052 in a system, it is recommended to follow a similar
methodology for implementing SPI communication. The
following is a summary of the SPI register controller:
1. Determine if Register 0x000 is not set to 0x3C.
2. If Step 1 is true, set Register 0x000 to 0x3C to enable the
SDO pin on the ADMV8052 and to allow SPI streaming
with Endian register ascending order.
3. Determine if the values have changed for any of the WRx
registers (Register 0x020 to Register 0x02F).
4. If Step 3 is true, write Register 0x020 to Register 0x02F by
pointing to Register 0x020 and streaming out 16 bytes of
data. The transaction is 144 bits in total (R/W bit + 15 address
bits + 128 data bits). Streaming out the data in this order
ensures that the switch position priority is WR0 to WR3.
5. If Step 4 has occurred, write dummy data to Address 0x0A.
Note that Address 0x0A does not exist in the ADMV8052,
and the written dummy data is ignored. This step is
microcontroller architecture dependent and can be ignored
in most cases. It is necessary for the
bus and reconfigure for a standard 24-bit SPI transaction.
SDP-S to clear the SPI
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EVAL-ADMV8052
6. Determine if the values have changed for any of the LUT
registers (Register 0x100 to Register 0x2FF).
7. If Step 6 is true, write to Register 0x100 to Register 0x2FF
by performing the following:
•
Pointing to Register 0x100 and streaming out 64 bytes
of data.
• Pointing to Register 0x140 and streaming out 64 bytes
of data.
•
Pointing to Register 0x180 and streaming out 64 bytes
of data.
• Pointing to Register 0x1C0 and streaming out 64 bytes
of data.
•
Pointing to Register 0x200 and streaming out 64 bytes
of data.
• Pointing to Register 0x240 and streaming out 64 bytes
of data.
•
Pointing to Register 0x280 and streaming out 64 bytes
of data.
• Pointing to Register 0x2C0 and streaming out 64 bytes
of data.
8. If Step 7 has occurred, repeat Step 5.
9. Write out any remaining registers that may have changed.
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