SPRADN4B October 2024 – September 2025 AM62P , AM62P-Q1
The recommendation is to implement the attached device (OSPI/QSPI memory) reset using a 2-input ANDing logic. Processor GPIO is connected as one of the input to the AND gate with provision for pullup (10kΩ or 47kΩ) (to support boot) near to the ANDing logic AND gate input and provision for 0Ω to isolate the GPIO output for testing or debug. The other input to the AND gate is the MAIN domain warm reset status output (RESETSTATz).
In case the processor MAIN domain warm reset status output (RESETSTATz) is directly used (without ANDing logic) to reset the attached device, the recommendation is to match the IO voltage level of RESETSTATz with the attached device. A level translator is recommended to match the IO level. A resistor divider can be used alternatively for level shifting, provided optimum value of the resistor divider is selected. If too high the rise/fall time of the OSPI/QSPI reset input can be slow and introduce too much delay. Use of too low value resistors as divider causes the processor to source too much steady-state current during normal operation.
The recommendation is to choose memory device that supports external reset input pin in addition to the data, clock, and chip select inputs.