2015-04-14 06:33 AM
Hi,
I want to use external SRAM with the controller STM32F429. i want to make use of internal supervisor circuit, which is used to power the internal RTC and internal 4Kb SRAM, to backup the data in external SRAM. for this i need to know following things1. is there any GPIO with default behaviour of going low when there is PDR (power down reset)2. is it possible to pogram any GPIO for this particular behaviour? ThanksVinay2015-04-14 07:57 AM
Is power down reset the right term here?
If you're doing the SLEEP/STOP/STANDBY you'd control the GPIO pins.There are a handful of pins documented to be in the low power domain, PC13,13,15 as I recall. Read the manual.Other pins that lose power aren't going to stay high, Try programming a GPIO pin as output, driven high, with a pull-down low. If that doesn't work as well as you want, try a very weak external pull-down.Look at the NRESET pin.You're going to have to do your own experiments.2015-04-14 09:13 PM