device start-up issue. any suggestions ? | Cypress Semiconductor
device start-up issue. any suggestions ?
I am facing a bring-up issue with a custom designed electronic assembly that is based on a CY5668LTI-LP014 IC in QFN-68.
Here is a quick description of the psoc project:
* The f/w program is a stand-alone application, it implements a basic configuration of a few digital input and output pins.
* The psoc project operates with internal ILO and IMO, no use of the crystal oscillators. It also does not make use of the internal boost converter since the IC is powered from externally regulated voltage source.
* All analog, logic core, i/o voltages seem OK and are @3.3V with low noise ~50mVpp.
* All analog and digital voltages and which are generated by the IC seem correct level ~0.9V, negligible noise and are externally de-coupled.
* Single H/W reset asserts/de-asserts as intended during device programming and user interaction, via dedicated XRESn pin (no use of 2nd optional pin).
* Device Flash NVM successfully programmed/verified using JTAG in self-powered mode.
Despite this, the firmware program fails to start-up and activate/toggle the digital i/o ports of the IC. For narrowing down the issue i have also connected the internal ILO (100kHZ) to one of the digital ports; the port assumes the correct start-up level (high or low as configured in the psoc project schematic) but the expected AC signal of the ILO is not appearing after power-up.
My conclusion is that something is interfering with internal ILO to start-up and prevents the program code to be copied form flash and execute.
My questions are:
Are there any configuration settings/trims which might affect the operation of the ILO, or brown-out detectors and which can be manipulated in the psoc project or fitter settings ?
Are there are any techniques which i can use to gain any insights as to what is preventing the embedded MCU to start up upon power-on and hardware reset ?
PS: Attached is the project schematic