Datasheet

AD9559 Data Sheet
Rev. C | Page 48 of 120
Repeat the process of programming the device control registers
for a new setup, storing a new upload sequence in the EEPROM
scratchpad (Step 1 through Step 4), and executing an EEPROM
upload (Register 0x0E02, Bit 0) until all of the desired setups
have been uploaded to the EEPROM.
Note that, on the final upload sequence stored in the scratchpad,
the pause instruction (0xFE) must be replaced with an end
instruction (0xFF).
To download a specific setup on demand, first store the
condition associated with the desired setup in Register 0x0E01,
Bits[3:0]. Then perform an EEPROM download (Register
0x0E03, Bit 1). Alternatively, to download a specific setup at
power-up, apply the required logic levels necessary to encode
the desired condition on the M1 to M0 multifunction pins.
(Note that only Condition 1 through Condition 3 are accessible
via the M pins.) Then power up the device; an automatic EEPROM
download occurs. The condition (as established by the M1 and
M0 multifunction pins) guides the download sequence and
results in a specific setup.
Keep in mind that the number of setups that can be stored
in the EEPROM is limited. The EEPROM can hold a total of
2048 bytes. Each nondata instruction requires one byte of
storage. Each data instruction, however, requires N + 4 bytes of
storage, where N is the number of transferred register bytes and
the other four bytes include the data instruction itself (one byte),
the target address (two bytes), and the checksum calculated by
the EEPROM controller during the upload sequence (one byte).