I'm trying to debug an application running on an Atmel SAM3U which
goes into sleep mode using "wfi" and only wakes up occasionally on
timer overflows, etc...

Access to the JTAG Debug Port (JTAG-DP) seems to work while in sleep
mode. However, accessing the control and status register (DHCSR) of
the debug core fails and causes a STICKYERR in the CTRL/STAT register
of the JTAG-DP. According to the Cortex-M3 TRM (Section 7.2.1) the
processor clock (HCLK) is disabled while in sleep mode until an
interrupt occurs (clock gating).

The following issue on the bug tracker
(http://sourceforge.net/apps/trac/openocd/ticket/28) suggests that a
power-up signal should be generated by the debugger to wake-up the
core, however, it seems that the corresponding bits in the CTRL/STAT
register (CDBGPWRUPREQ and CSYSPWRUPREQ) of the JTAG-DP are already
set when the debug port is initialized by openocd.

Is there any other way to wake-up the processor through the JTAG-DP
while in sleep mode?

Regards,
Philipp

------------------------------------------------------------------------------
Live Security Virtual Conference
Exclusive live event will cover all the ways today's security and 
threat landscape has changed and how IT managers can respond. Discussions 
will include endpoint security, mobile security and the latest in malware 
threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/
_______________________________________________
OpenOCD-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/openocd-devel

Reply via email to