5.1.1. The Multi-ICE server fails to autoconfigure the chip

The following can be the cause of this problem:

The chip contains devices that are not supported by autoconfiguration

If the autoconfiguration process detects a working TAP controller attached to an unknown device, a TAP box is shown in the server window labeled UNKNOWN. The list of supported devices is in the file proclist.txt. If autoconfiguration of your device is not supported there are two alternatives:

  • Use manual configuration. See Manual device configuration.

  • Double click the TAP box. A dialog box appears that shows the IR length for the detected TAP controller. If you only have one device in your chip with this IR length (excluding devices that are autoconfigurable), you can tell the server what the device is. To do this add a file called USERDRVn.TXT (where n is the IR length) to the Multi-ICE installation directory. The file must contain the name of the device to use on the first and only line in the file. For example, if you have a DSP with an IR length of 4, add a file called USERDRV4.TXT that contains the text DSP.

You have a signal fault

The most common faults are:

  • There is no pull-up resistor on the nTRST signal. This signal has an open collector drive from the Multi-ICE interface unit. There is no pull-up in the unit. In the EmbeddedICE interface unit this signal was driven with a push-pull driver so no pull-up was required (although it is specified as being required).

  • Signals nTRST and nSRST are not correctly driven by the target. Details on driving these signals correctly are in Chapter 6 System Design Guidelines.

  • The TCK frequency is too high for the chip. The following circumstances are known to cause this:

    • When using a simulated TAP controller in a Quickturn/IKOS unit. In this case the default frequency of 1MHz might be too high. Try autoconfiguring at 20kHz instead by selecting File ? Autoconfigure at 20KHz. If this fails, manually configure the server.

    • Using a chip whose MCLK setting is much slower than 1MHz. A common example is a telephone pager or similar device that contains power-saving (sleep mode) circuitry. On some boards the software can write to a register to switch the clock frequency between fast, for example 20MHz, and slow, say 25kHz. If the processor MCLK is running at 25kHz then autoconfiguration fails. Try autoconfiguring at 20kHz instead. If this fails, manually configure the server.

    The default TCK frequency for autoconfiguration is 1MHz. For all normally working chips this is not a problem.

The server cannot stop the processor during autoconfiguration

This results in UNKNOWN being displayed in the TAP controller box. The most common cause is that the processor has not been reset properly. Press the reset button and retry autoconfiguration. If this fails, check that the processor reset line is not continuously asserted (held LOW). If it is, find and fix this problem, and try autoconfiguring again.

There is insufficient or no power to the Multi-ICE interface unit

Multi-ICE requires between 2V and 5V DC on pin 2 of the 20-way JTAG connector, or between 9V and 12V DC on the external power input jack, and a power source that can deliver sufficient current (see Power supply for more details). If you are using a PID board with an ARM7TDMI header card, resistor R1 must be shorted out in order to deliver this.

When the Multi-ICE interface unit is correctly powered, the Power LED is brightly lit.

There is some other problem with the TAP controller

Other possibilities include:

  • The signal nTDOen is not correctly implemented. The nTDOen signal is used to enable the pad tristate driver for the TDO pin.

  • The target hardware is driving nWAIT permanently LOW, or alternatively, HWAIT or BWAIT permanently HIGH. These signals gate the processor core clock, preventing the EmbeddedICE logic from taking the core into debug state. If this is happening, it usually indicates a fault in the hardware.

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