Problem using Sleep and Deep sleep in the same application

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by cgroen on Tue Mar 04 01:25:42 MST 2014
I am having some problems with our application. Basically it is a LPC1778 using Keil RTX etc.

When I let the device enter Deepsleep for some time (wake up by external IRQ on a GPIO pin) it works just fine (I reenable PLLs etc).
But, when I, at some point after the device has been waken up, puts the device in Sleep (using os_idle_demon() in Keil RTX) the device resets immediatly. It does not matter how long or short time there is between the exit from deepsleep and to the sleep, the reset happens every time. If I don't enter Sleep everything works perfect (I can enter deepsleep as many times as I want and it just keeps working). The RSID register shows 0x18 after reset (BODR and SYSRESETREQ) which makes no sense. The VddReg3v3 is monitored and is rock solid in all circumstances and SYSRESETREQ is not set by the software.

I have asked for input on the Keil forum: http://www.keil.com/forum/24880/
but so far no real good explanations.

Maybe someone here can give some pointers or ideas what to look for ?

I have asked NXP support for help on this, but no answer for 2 weeks now :(