Øyvind, as you can see from this presentation, http://focus.ti.com/lit/ml/sprp603/sprp603.pdf , the ICEPick works as a JTAG Route Controler(JRC), which allows you to insert and remove TAPS from the scan chain. the davinci board DM355 has the exact same ICEPick as the OMAP 3530 beagle board, however with one difference, the EMU0/EMU1 lines when pulled low on the divinci create a hardwired enable for the ARM core to be present in the scan chain. here is the table describing that functionality:
0 0 ICEPick + default TAP(s) 0 1 ICEPick Reserved 1 0 ICEPick Wait-in-reset 1 1 ICEPick Default condition NOTES: ICEPick is always in the scan chain Default TAPs are the ARM and the ETB the problem with the OMAP3530 is that there are no default TAPS which means that when EMU0/EMU1 is set low, the only item available is the ICEPick. in order to work with the OMAP3530 a process of turning off the "ICEPick Bypass Switch" has to occur. TI provide the sequence need to do this: http://www.elinux.org/OMAP3530_ICEPICK in addition this information can also be learned from the openly available BDI config: http://www.elinux.org/BeagleBoardJTAG#BDI_config the core issue for openocd is that the scanchain starts up with only the ICEPick available. after startup, a script of ir/dr functions needs to be executed to turn off the bypass. once this is done, the chain needs to be rescanned/reverified for the existance of the arm core. due to the number of multi-core arm devices becoming available, a vast majority of the vendors will be providing JRC's as their primary means of jtag. dave --- On Mon, 10/13/08, Øyvind Harboe <[EMAIL PROTECTED]> wrote: > From: Øyvind Harboe <[EMAIL PROTECTED]> > Subject: Re: [Openocd-development] JTAG emulator with openocd for beagleboard > To: "Dirk Behme" <[EMAIL PROTECTED]> > Cc: [email protected] > Date: Monday, October 13, 2008, 3:31 PM > > Some developers are working on OpenOCD support for > Beagle/OMAP35xx > > using Flyswatter. As far as I know, the main issue is > that OpenOCD > > doesn't support the "new" JTAG > architecture of OMAP35xx at the moment. > > I.e. you first have to add DAP to the TAP router, via > a programming > > sequence, then ARM core can be accessed. > > Can you post some details on this to this mailing list? > > The last time this was discussed in openocd development > mailing list > there was various other issues that had to be addressed > that got > in the way... (reset as I recall)... but that should be > sorted now. > > -- > Øyvind Harboe > http://www.zylin.com/zy1000.html > ARM7 ARM9 XScale Cortex > JTAG debugger and flash programmer > > Free eCos workshop in Oslo October 21! > http://www.zylin.com/workshop.html > _______________________________________________ > Openocd-development mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/openocd-development _______________________________________________ Openocd-development mailing list [email protected] https://lists.berlios.de/mailman/listinfo/openocd-development
