Connection Test Parameters

This is an optional section in the project file preamble that can be used to modify the way that the connection test is implemented.

Syntax

CONNTEST
    TEST := CONNTEST;
    MAX_NETS := INTEGER;
    INDIRECT := [ ALL | CONNECTION ] ;
    ONE_WAY := [ TRUE | FALSE ] ; 
    DOT6ENABLE := [ TRUE | FALSE ] ;
    DOT6TIME := INTEGER;
    LOGICENABLE := [ TRUE | FALSE ] ; 
END;

"CONNTEST" is the normal connection test. It can take several parameters.

MAX_NETS

This limits the number of nets that may change value simultaneously, helping to prevent ground bounce during the test.

INDIRECT

This controls how many nets will be tested for indirect shorts (shorts via a resistor) during the connection test. The default is to test all nets for indirect shorts; set INDIRECT := CONNECTION; to restrict testing for indirect shorts to only those nets which contain components in the CONNECTION LIST. This should only be necessary if you are seeing spurious errors from the connection test, which can happen if floating nets mimic the behaviour of this type of short.

ONE_WAY

This controls whether nets will be tested for one-way indirect shorts (via a buffer and a resistor) during the connection test. By default, such errors are ignored, as floating nets may mimic this type of error.

DOT6ENABLE

If the circuit contains JTAG devices compliant with the 1149.6 standard this controls whether or not the connection test should run in advanced 1149.6 mode. By default the tests are run. In order to get the best results from the test, the INDIRECT option should be set to ALL

DOT6TIME

This specifies the minimum number of microseconds to wait between each JTAG scan whilst performing 1149.6 tests. Setting a value for this field will override any automatically determined settings for the timing of 1149.6 testing AND will override any times or numbers of pulses set for individual JTAG devices. Normally this field should not need to be set, in which case default behaviour is to fulfil the settings for individual devices as determined from their BSDL files and user settings.

LOGICENABLE

This specifies whether connections that pass through logic devices should be tested or not. If not specified, then it defaults to TRUE.

Example

CONNTEST
    TEST := CONNTEST;
    MAX_NETS := 20;
    INDIRECT := ALL;
END;