nSTATUS has the following two functions:
- To behave as an acknowledge for nCONFIG.
- To behave as an error status signal. It is important to monitor nSTATUS to identify configuration failures.
Generally, the Intel® Agilex™ device changes the value of nSTATUS to follow the value of nCONFIG, except after an error. For example, after POR, nSTATUS asserts after nCONFIG asserts. When the host drives nCONFIG high, the Intel® Agilex™ device drives nSTATUS high.
In previous device families the deassertion of nSTATUS indicates the device is ready for configuration. For Intel® Agilex™ devices, when using Avalon® -ST configuration scheme, after the Intel® Agilex™ device drives nSTATUS high, you must also monitor the AVST_READY signal to determine when the device is ready to accept configuration data.
nSTATUS asserts if an error occurs during configuration. The pulse ranges from 0.5 ms to 10 ms.
nSTATUS assertion is asynchronous to data error detection. Intel® Agilex™ devices do not support the auto-restart configuration after error option.
Previous device families implement the nSTATUS as an open drain with a weak internal pull-up. Intel® Agilex™ always drives nSTATUS. Consequently, you cannot wire OR an Intel® Agilex™ nSTATUS signal with the nSTATUS signal from earlier device families.
nSTATUS must be pulled high externally and the SDM must sample nSTATUS high when VCCIO_SDM ramps up to the recommended operating voltage.