Method for detecting signal transfer errors in near real time in a digital system

The method for detecting signal transfer errors in a digital logic system that might occur in a transfer medium between a source device and a destination device, the method comprising:

• sending a second diagnostic signal from the source device through the transfer medium to the destination device;
• comparing at the destination device the second diagnostic signal with a first comparator signal derived from a stored diagnostic signal to determine if a signal transfer error has occurred;
• sending a first diagnostic signal from the source device through the transfer medium to the destination device, the first diagnostic signal being an inverted form of the second diagnostic signal;
• and
• comparing at the destination device the first diagnostic signal with a second comparator signal derived from the stored diagnostic signal to determine if a signal transfer error has occurred.

A method for detecting signal transfer errors in a digital logic system that might occur in a transfer medium between a source device and destination device, the method comprising:

• storing in the destination device a second multi-bit diagnostic signal;
• sending a first multi-bit diagnostic signal from the source device through the transfer medium to the destination device;
• comparing the first multi-bit diagnostic signal received by the destination device with the second multi-bit diagnostic signal to determine if a signal transfer error has occurred;
• inverting the first multi-bit diagnostic signal;
• sending the inverted first multi-bit diagnostic signal from the source device through the transfer medium to the destination device;
• and
• comparing the inverted first multi-bit diagnostic signal received by the destination device with the second multi-bit diagnostic signal to determine if a signal transfer error has occurred.

Apparatus for detecting signal transfer errors in a digital logic system that might occur in a transfer medium between a source device and a destination device, comprising:

• means for storing in the destination device a second diagnostic signal;
• means for sending a first diagnostic signal and an inverted first diagnostic signal from the source device through the transfer medium to the destination device;
• means for using the first diagnostic signal for a comparison with the second diagnostic signal to determine if a signal transfer error has occurred;
• and
• means for using the inverted first diagnostic for a comparison with the second diagnostic signal to determine if a signal transfer error has occurred.

Apparatus detecting signal transfer errors in a digital logic system that might occur in a transfer medium between a source device and a destination device, comprising:

• in the source device:
• storage storing a first diagnostic signal;
• and
• a first multiplexer receiving the first diagnostic signal from the storage, the multiplexer alternately passing to the transfer medium the first diagnostic signal or its inverse on successive diagnostic cycles;
• in the destination device:
• storage storing a device diagnostic signal;
• a second multiplexer receiving the diagnostic signal passed from the first multiplexer to the transfer medium, the second multiplexer alternately passing to a comparator the received diagnostic signal or its inverse on successive diagnostic cycles;
• and
• a comparator comparing the second diagnostic signal with the diagnostic signal passed by the second multiplexer to determine if a signal transfer error has occurred.

A method for detecting signal transfer errors in a digital logic system that might occur in a transfer medium, the method comprising:

• providing a system clock having clock cycles during which data signals are sent from the source device to the destination device and a clock cycle during which a diagnostic signal is sent from the source device to the destination device;
• storing in the destination device a second diagnostic signal;
• sending data signals during the data signal clock cycles from the source device on the signal path through the transfer medium to the destination device;
• sending a first diagnostic signal during the diagnostic signal clock cycle from the source device through the transfer medium to the destination device on the same signal path that the data signals are sent from the source device to the destination device;
• comparing the first diagnostic signal received by the destination device with the second diagnostic signal to determine if a signal transfer error has occurred;
• inverting the first diagnostic signal;
• sending the inverted first diagnostic signal from the source device to the destination device;
• and
• comparing the inverted first diagnostic signal received by the destination device with the second diagnostic signal to determine if a signal transfer error has occurred.