Method and apparatus for detecting a data receiving error

A receiver operative for receiving an asynchronous data signal, said receiver comprising:

• a clock recovery unit operative for receiving said asynchronous data signal and for producing a clock signal corresponding to said asynchronous data signal;
• a sampling gate operative for receiving said asynchronous data signal and said clock signal as input signals, and for producing a sampled data signal, said sampled data signal corresponding to said asynchronous data signal and synchronized with said clock signal;
• a first counter for receiving said asynchronous data signal, said first counter operative for counting each pulse contained in said asynchronous data signal;
• a second counter for receiving a sampled data signal, said second counter operative for counting each pulse contained in said sampled data signal;
• a subtractor circuit for subtracting the value of said second counter from the value of said first counter, and generating a result value;
• and
• an error indication circuit for monitoring the result value of the subtractor and for generating an error signal when said result value exceeds a predetermined value.

A method of detecting a sampling error, said method comprising the steps of:

• inputting a serial data signal to a first counter, said first counter operative for counting each pulse contained in said data signal;
• inputting a sampled data signal into a second counter, said second counter operative for counting each pulse contained in said sampled data signal;
• subtracting the value of said second counter from the value of said first counter, and generating a result value;
• and
• generating an error signal when said result value exceeds a predetermined value.