JAJSSV2G March 2011 – January 2024 DAC3482
PRODUCTION DATA
In Single Sync Source mode, the FIFO write and read pointers are reset from the same source, either LVDS FRAME or LVDS SYNC signal. As described in the Section 6.3.3, this mode has latency variations in both the FIFO Out clock and DAC clock between the multiple DAC devices. Applications requiring exact output latency control will need Dual Sync Sources mode instead of Single Sync Source mode. A single rising edge for FIFO and clock divider is recommended in this mode. Periodic sync signal is not recommended due to non-deterministic latency of the sync signal through the clock domain transfer.
In this mode, there is a chance for FIFO pointers 2 away alarm (or possibly 1 away alarm) to occur at initial setup/syncing. This is the result of Single Sync Source mode having 0 to 3 address location slip, which is caused by the asynchronous handoff of the sync signal occurring between the DATACLK zone and DACCLK zone. The asynchronous relationship between the clock domains means there could be a slip (from nominal) in the READ and Write pointers at initial syncing. For example, with the default programming of FIFO Offset of 4, the actual FIFO Offset may be 3, 2, or in some instances, 1. Please note that in this mode, the nominal address location slip is 0 with the possibility getting less for each increase in slip amount. Also, the slip does not continue to occur as the device functions, but the READ/WRITE pointers may not be at optimal settings.
In situation of alarm occurrence:.