| 摘要 |
A method of generating a representation, such as an eye diagram, of an electrical signal comprises sampling the signal using a first data sampling module 9 at the centre of a bit cell and, for each bit cell, also sampling at a horizontal and vertical offset using a second data sampling module 10. The first data samples are compared against a first threshold and the number of logical ones in the sampled data is counted at module 17. The second data samples are compared against a second threshold and the number of logical ones is counted with module 18. The second count is used to correct the first count in a correction step 19. Vertical differentiation 20 of the corrected data produces an eye diagram. The offset sampling may be performed for many different horizontal and vertical offsets. Jitter, distortion, pulse width, amplitude, rise time or overshoot may be indicated via the eye diagram. |
