SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
When reprogramming the MUXMODE, DELAYMODE, and MODESELECT fields of a pad configuration register or the CFG_x_IN, CFG_x_OEN, and CFG_x_OUT registers in the IODELAYCONFIG Module, there is potential for a glitch on the corresponding IO. Therefore, the device IOs should be isolated when writing to any of these fields. Isolating the IOs forces them to tri-state output with internal pulls holding their previous levels. De-isolating the IOs returns their control to the selected peripheral modules.
While the IOs are Isolated, code must execute only from internal RAM and the isolated IO interfaces should not be actively used.
Isolation is a global event that affects all LVCMOS IOs except for the following:
Isolation/De-isolation of the device IOs is accomplished via the following sequences:
Isolation Sequence:
De-isolation Sequence:
Configuration of the pad configuration registers is normally done as part of the IO Delay Recalibration Sequence described in Section 18.4.6.1.8, IO Delay Recalibration, which references the above Isolation/De-isolation sequences.