Quote of the Day

This... is [the isle of] Berk. It snows nine months of the year... and hails the other three.

— Introduction from How to Train Your Dragon. I feel this way about Minnesota every February.

I test high-speed serial channels every day. The most common test parameter that I need to measure is the Bit Error Rate (BER). Figure 1 shows the most common test configuration used for measuring BER. Because bit errors occur randomly, there is a certain amount of error involved in measuring the parameter. So when you state a BER measurement, you also give a confidence interval to express your level of uncertainty.

I recently was asked how to compute the test time required to verify the Bit Error Rate (BER) of a serial transport at various confidence levels. Test time is important because it drives test cost. I decided to make a spreadsheet that uses a data table and VBA to compute the test time as function of the number of bit errors during the testing and the desired confidence level. While I have discussed this topic in another blog post, I did not provide a spreadsheet for computing the values. The spreadsheet included here resolves this shortcoming. You just need to put in your bit rate and push the button.