TM4C1294KCPDT: tm4c1294kcpdt

Diagnosing a precise bus fault error is described in section 3.2 starting on page 6 of http://www.ti.com/lit/an/spma043/spma043.pdf. As you already determined, this was a data read or write to address 0xFFFFFFFF, which indeed should cause a fault. Continue following the steps in the above application report onto page 8 and it will show you how to identify the address that cause the fault. 

Bob,

Staff/I wish to memorialize your writing as a, 'General Problem-Solving Method' - which proves (almost) always far superior to a 'One-Off' copy/paste 'solution.'

You've nicely provided the reference document - introduced its usage - and have 'Set the Stage for (real)  Poster Learning & Understanding!'

TAG:  a 'solution method' as opposed to a quick/dirty/eased (learning-lite) 'copy/paste'

Hi Bob,

Based on the reference document fault address read and trying to locate in disassembly it showing following message

Memory map prevented reading 0xFFFFFFFF [code=0x20000]

fault address details  are 

Did you examine the stack contents, find the address of the instruction that caused the fault and look at the disassembly? Knowing what function that instruction is in will often help. Look at the parameters passed to that function (directly or indirectly) and you will likely find the problem.

Hi Bob,

While analyzing the call stack of these

It will point to USB library.

It finally point to USBDeviceIntHandlerInternal  function which is in usb library..

Is it problem with library?..

Regards

Nikhil

No, I don't think it is a problem of the library, but more likely the initialization of the USB descriptor block. What version of TivaWare are you using? The line numbers given above don't line up with the function names in usbdenum.c from version 2.1.4.178. 

Hi Bob,

I am using version of 2.16.0.08.

Please check the attachment..

0601.usbdenum.c

Regards

Nikhil

Is this a duplicate of this: https://e2e.ti.com/support/microcontrollers/other/f/908/t/850106

Hi Todd,

Actually it is different testing condition.

Regards

Nikhil

Nikhil,

Let's resolve the other one first. The test case might be different, but I expect the underlying issue is the same. Sean had a couple questions for you on the other thread.

Todd