Hi everybody, just a quick question. Can the PowerPC in a Virtex II Pro, be routed to control the JTAG hardware? By that I mean provide instruction and data to the TAP Thanks!!
PowerPC and JTAG
Started by ●January 21, 2004
Reply by ●January 26, 20042004-01-26
Yes. There is an internal JTag tap that can be "tapped into" If you want to use the PPC Jtag you have to use the internal tap symbol. Also If you load via the select map you can have pins from the Xilinx route outside to the jtag pins. I sure there are other ways also. Steve "BrakePiston" <brakepiston@REMOVEyahoo.co.uk> wrote in message news:h6qs001vj8noonjnh9mbdocdsc5iu1ve16@4ax.com...> Hi everybody, just a quick question. > > Can the PowerPC in a Virtex II Pro, be routed to control the JTAG > hardware? By that I mean provide instruction and data to the TAP > > Thanks!! > > >
Reply by ●January 29, 20042004-01-29
"Steve Casselman" <sc_nospam@vcc.com> wrote in message news:<MEjRb.16624$un.13640@newssvr27.news.prodigy.com>...> Yes. There is an internal JTag tap that can be "tapped into" If you want to > use the PPC Jtag you have to use the internal tap symbol.Is this really true? I thought the only way you could drive the JTAG pins was with external connections from other IO pins. The only reference I could find to JTAG tap is the way the PPC taps into the JTAG instruction register so the length doesn't vary depending on whether the PPC is used or not. Could you cite a reference? Alan Nishioka alann@accom.com
Reply by ●January 29, 20042004-01-29
Alan, Page 260 of the PowerPC Processor Reference Guide covers JTAG for the 405PPC. www.support.xilinx.com and go to the /documentation/users guides/Device Families/Virtex-II Pro/ Austin Alan Nishioka wrote:> "Steve Casselman" <sc_nospam@vcc.com> wrote in message news:<MEjRb.16624$un.13640@newssvr27.news.prodigy.com>... > >>Yes. There is an internal JTag tap that can be "tapped into" If you want to >>use the PPC Jtag you have to use the internal tap symbol. > > > Is this really true? I thought the only way you could drive the JTAG > pins was with external connections from other IO pins. The only > reference I could find to JTAG tap is the way the PPC taps into the > JTAG instruction register so the length doesn't vary depending on > whether the PPC is used or not. > > Could you cite a reference? > > Alan Nishioka > alann@accom.com
Reply by ●January 30, 20042004-01-30
Austin Lesea <austin@xilinx.com> wrote in message news:<bvc7np$eer1@cliff.xsj.xilinx.com>...> Page 260 of the PowerPC Processor Reference Guide covers JTAG for the > 405PPC.Right, but I think the OP was asking if you could *drive* JTAG from the PPC and I didn't think this was possible (w/o external connections). I want to do this so I can update flash using JTAG and the internal PPC. Alan Nishioka alann@accom.com
Reply by ●January 30, 20042004-01-30
Alan, Since the PPC is all inside the FPGA, and you have to instatiate the JATG to get access to the PPC, I imagine you can wire it anywhere you want in the fabric.... Austin Alan Nishioka wrote:> Austin Lesea <austin@xilinx.com> wrote in message news:<bvc7np$eer1@cliff.xsj.xilinx.com>... > >>Page 260 of the PowerPC Processor Reference Guide covers JTAG for the >>405PPC. > > > Right, but I think the OP was asking if you could *drive* JTAG from > the PPC and I didn't think this was possible (w/o external > connections). > > I want to do this so I can update flash using JTAG and the internal > PPC. > > Alan Nishioka > alann@accom.com
