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This study focuses on reducing crosstalk between clock and psout signals and presents long time test results of a 40 MHz SEU test system. Findings show improved crosstalk reduction and stable performance at higher frequencies.
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Progress on the 40 MHz SEU Test System based on DE2 Board Feb. 01, 2010 In CPPM By Zhao Lei
Test about the crosstalk from clock to psout signals from SEU chip to interface board Waveform of the ‘psout’ signal of Channel 5 Waveform of the ‘psout’ signal of Channel 6
Test about the crosstalk from clock to psout signals from SEU chip to interface board Waveform of the ‘psout’ signal of Channel 6 when 1 wire is used as ground line Waveform of the ‘psout’ signal of Channel 6 when 2 wires are used as ground lines After modification of the transmission of the clock signal
Long Time Test Results--Test Mode 0 : static test without read back
Long Time Test Results--Test Mode 1 : static test with read back
Long Time Test Results--Test Mode 2 : Test versus frequency based on latches
Long Time Test Results--Test Mode 3 : Test versus frequency based on DFFs
Waveform of the psout signals (blue) and error signal (red) in FPGA as for data pattern “11111” in Test mode 3
Waveform of the psout signals (blue) and error signal (red) in FPGA as for data pattern “00000” in Test mode 3
Conclusion • The crosstalk from the clock to psout signals could be greatly reduced by better shielding of ground. • From the long time test, the FPGA and software is approved to work well and stably in long time. • The system could run up to 40 MHz, and no errors occur for the first 3 test modes. Errors occur in test mode 3 with very low Bit Error Rate, which are probably due to ground, power supply or the electronic characteristics of the chips.