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Altera_Forum's avatar
Altera_Forum
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15 years ago

JTAG can’t find device

Hi all,

I am a beginner of Altera's device.

Today, When I use the JTAG mode of Quartus’ programmer to configure the device EP3C5E144, the programmer always says “Unable to scan device chain. Can’t scan JTAG chain.”

When the programmer tried to scan the chain, I test the TDI, TDO, and TCK. There is data wave on TCK and TDI, but the TDO never changed and always hold about 2.2V.

All the power, 1.2V, 2.5V, 3.3V, is OK. I used 2.5V to power the JTAG connector, and added a 1k resistor between 2.5V and 3.3V (pin 6).

Besides, NCE holds 0V. Though I have pulled up the signals, Config_done and nstatus, they all keep 0.033V.

I also use a flash to configure the FPGA in AS mode. The programmer can download code to flash successfully, however the FPGA shows no action no matter I re-power up the system or not, and there is no clock on DCLK.

The Usb blaster should be right, because I can configure some other boards. Could anybody give me some suggestion?

18 Replies

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  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    Dear all:

    I have the same problem with ytggsitp when configuring the device EP3SL340H1152. the VVCCIO of

    bank 1A is 2.5V.When the programmer tried to scan the chain, I test the TDI, TDO,TMS and TCK.

    There is data wave on TCK ,TMS and TDI, but the TDO never change and always hold about 0 V(Why?I think the output of TDO should be at 2.5V at the begining,am I right?? ). All the power is OK.

    Thank you very much!!!:)
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    --- Quote Start ---

    Well if your usb blaster is ok, all the connections are right and there's activity on all JTAG input signals, probably your device is broken.

    Any chance you could post the schematics of your design?

    -- Ton

    --- Quote End ---

    Dear Ton:

    I have the same problem with ytggsitp when configuring the device EP3SL340H1152. the VVCCIO of

    bank 1A is 2.5V.When the programmer tried to scan the chain, I test the TDI, TDO,TMS and TCK.

    There is data wave on TCK ,TMS and TDI, but the TDO never change and always hold about 0 V(Why?I think the output of TDO should be at 2.5V at the begining,am I right?? ). All the power is OK.

    Thank you very much!!!
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    Difficult to say, with this little information. Is there a chance you could post your schematic?

    TDO is high-Z in the beginning. So you should see a high on this pin, if it has a pull-up resistor.

    -- Ton
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    --- Quote Start ---

    Difficult to say, with this little information. Is there a chance you could post your schematic?

    TDO is high-Z in the beginning. So you should see a high on this pin, if it has a pull-up resistor.

    -- Ton

    --- Quote End ---

    Thank you very much !
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    --- Quote Start ---

    Difficult to say, with this little information. Is there a chance you could post your schematic?

    TDO is high-Z in the beginning. So you should see a high on this pin, if it has a pull-up resistor.

    -- Ton

    --- Quote End ---

    Thank you very much!!
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    The Vccpd = Vccio1A = 2.5V

    The program connector is powered by V_3.3

    These should be the same (either V_3.3 or 2.5V).

    nSTATUS and nCONFIG and CONFIG_DONE should be pulled-up to Vccpgm, which is 3.3Vcc, not V_3.3.

    Maybe these are supposed to be the same, but in your schematic the labels differ.

    Pull-up JTAG to Vccpd.

    Pull-up other programming pins to Vccpgm.

    Good luck, Ton
  • Altera_Forum's avatar
    Altera_Forum
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    15 years ago

    Now I get Vccpgm = Vccpd = Vccio1A = 2.5V and the program connector powered by V_3.3.

    nSTATUS 、nCONFIG and CONFIG_DONE are all pulled-up to Vccpgm which

    is 2.5V.

    However,the question still exists. when operating autodetector, both device chain and JTAG chain couldn't be scaned. It's puzzled to me that TDO still holds low level and is never changed. However, it works well in the PS mode configuration. In addition, it is nornal for the output of Bank 1A that TDI, TDO TCK and TMS belongs to.

    Many thanks!Best wishes to you!
  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    15 years ago

    --- Quote Start ---

    The Vccpd = Vccio1A = 2.5V

    The program connector is powered by V_3.3

    These should be the same (either V_3.3 or 2.5V).

    nSTATUS and nCONFIG and CONFIG_DONE should be pulled-up to Vccpgm, which is 3.3Vcc, not V_3.3.

    Maybe these are supposed to be the same, but in your schematic the labels differ.

    Pull-up JTAG to Vccpd.

    Pull-up other programming pins to Vccpgm.

    Good luck, Ton

    --- Quote End ---

    Now I get Vccpgm = Vccpd = Vccio1A = 2.5V and the program connector powered by 2.5V.

    nSTATUS 、nCONFIG and CONFIG_DONE are all pulled-up to Vccpgm which

    is 2.5V.

    However,the question still exists. when operating autodetector, both device chain and JTAG chain couldn't be scaned. It's puzzled to me that TDO still holds low level and is never changed. However, it works well in the PS mode configuration. In addition, it is nornal for the output of Bank 1A that TDI, TDO TCK and TMS belongs to.

    Many thanks!Best wishes to you!