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Runtime Pin Errors and Warnings

There are a number of runtime warnings and errors that XJEase may create when driving and reading pins in a device file:

ERROR: Cannot read pin 14 (bit 0 of bus Addr) on device IC5. The net is not readable.

To be able to read a bus, each pin on the bus must be connected to a readable pin on a JTAG or External Hardware device. If the bus is read from a JTAG pin, the JTAG device must be in a JTAG chain which is enabled in the Profile in which the current test is running. Alternatively if the value is to be read via External Hardware then that machine must be enabled in the Profile in which the test is run.

Warning: Cannot write to pin 14 (bit 0 of bus Addr) on Main.IC5. The net is not readable.

This warning will be displayed at runtime to indicate that the pin cannot be driven. It is a warning, rather than an error, because pins are often held at a suitable state by the PCB design.

ERROR: Cannot read pin 14 (bit 0 of bus Addr) on device IC5. The net can only be read by the current test device.

ERROR: Cannot read pin 14 (bit 0 of bus Addr) on device IC5. The net can only be driven from the current test device.

It is possible to have an XJEase device file for a JTAG device, so that its pins are driven from another JTAG device whilst the device being tested is held in BYPASS. During these tests, however, the pins on the device being tested must be driven / read from other JTAG pins on the net.

ERROR: Cannot disable pin 14 (bit 0 of bus Addr) on device IC5 to read it. The net is always driven by pin Main.IC3.12.

If you try to read a pin with a SET statement, then if there is a buffer pin (a pin which always drives) on the net, this will not be possible.

To read such a pin, use :=* rather than := in the SET statement.

ERROR: Cannot disable pin 14 (bit 0 of bus Addr) on device IC5. This pin is output only.

If a bus contains a buffer pin (which cannot be disabled), trying to disable it by setting it to I will fail.

ERROR: Cannot disable pin 14 (bit 0 of bus Addr) on device IC5. There is no output pin.

If a bus contains a pin that can only be read and not driven, trying to disable it (setting to I) will fail.

ERROR: Cannot read pin 18 (bit 0 of bus Data) on device IC5. The input pin for that net is a bidir pin which is currently outputting: Main.IC1.26

You will see this error if you try to use the :=*; operator on a net which only has access through a bidirectional pin. See the SET statement for more information about using :=*.