Dear TI experts,
apparently there is a condition that causes a complete hang of the OMAP L137.
By "complete hang" I mean the state for which my XDS560v2 STM emulator declares:
"Trouble Halting Target CPU:
(Error -1032 @ 0x3FE)
Data bus is 'not ready'. Choose 'Abort to try to abort the pending
transaction. Chose 'Force' to try to force the bus ready state.
(Emulation package 5.0.747.0)"
when I try to connect to the ARM core
"Trouble Halting Target CPU:
(Error -1060 @ 0x0)
Device is not responding to the request.
Reset the device, and retry the operation.
If error persists, confirm configuration, power-cycle the board, and/or try more reliable JTAG settings *e.g. lower TCLK).
(Emulation package 5.0.747.0)"
when I try to connect to the DSP core
The only way to exit this state is a complete power cycle of the OMAP device.
Resetting is not enough as well as all of the operations suggested by the emulator.
The condition under which I can create this state is the following:
- the ARM core executes instructions located in SDRAM (adresses 0xC000xxxx)
- the ARM core runs a simple endless loop that reads a valid location in the internal shared RAM.
- the DSP core runs instructions located in the internal RAM (addresses 0x1180xxxx)
- the DSP core runs a simple endless loop that reads a location at address 0xBC000000
Note that the address 0xBC000000 corresponds to a memory region where nothing should be present, according to L137 specs.
The access to this memory location mimics a bug that was present in my application code (an uninitialized pointer).
I tried other addresses in around 0xBC000000 and I found that, as an example:
- 0xB0000000 works fine
- 0xBCDE0000 fails
Note that if I let either of the two cores running alone, no issue occurs.
As soon as I run both cores together, the OMAP enters in the "complete hang state".
Please help me in understanding why this is happening and, if you confirm my diagnosis, how I can prevent this state to be entered.
Thank you very much in advance for your help.
regards
Ernesto