JAJSLU6B May 2023 – March 2024 DAC39RF10 , DAC39RFS10
PRODUCTION DATA
The NCO blocks can be synchronized using the LSB of the "I" input of the DUC0 channel on the JESD204C interface in complex input JMODES. Control bits that replace the LSB of the data samples are used to reset the NCO phase or an NCO frequency change. Table 7-11 show how the SYNC bit replaces the I sample LSB when using LSB replacement. The LSB replacement mode is enabled when the SPI_SYNC register bit is high while NCO_SYNC_SRC is set to 3. To trigger the event, the LSB must be low for 4 or more consecutive samples, and then high for 4 consecutive samples. The sync coincides with the 4th high sample arriving at the DUC0 input. When using the SPI interface to update the NCO frequency word, the user must set SPI_SYNC back to 0 to change back to the LSB representing I sample data. When using the FR interface to update the NCO, the LSB changes back to representing the I sample data after the synchronization event is triggered.
BIT | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
I Sample | I[15:1] | Sync | ||||||||||||||
Q Sample | Q[15:0] |