Tektronix MSO46 — понимание измерений DDR: ключевые параметры и алгоритмы [596/628]

Vix(ac) (DDR)

Vix(ac) is the differential input cross-point voltage measured from the actual crossover voltage and its complement signal to a

specified reference voltage. This is measured on the single ended signal.

DDR Time Measurement algorithms

DDR measurements require option 6-DBDDR3 (6 Series MSO instruments only).

tRPRE (DDR)

tRPRE is the width of the Read burst' preamble. This is measured from the exit of tristate to the first driving edge of the

differential strobe.

tWPRE (DDR)

tWPRE is the width of Write burst preamble. It is measured from the exit of tristate to the first driving edge of the differential

strobe.

tPST (DDR)

tPST is the width of Read or Write burst postamble. It is measured from the last falling edge crossing mid reference level to the

start of an undriven state (judged by a rising trend as per JEDEC specification).

Hold Diff (DDR)

Hold Diff is the elapsed time between the designated edge of the single ended waveform and the designated edge of a

differential waveform. The closest single-ended waveform edge to the differential waveform edge that falls within the range limits

is used for the measurement.

Setup Diff (DDR)

Setup Diff is the elapsed time between the designated edge of a single ended waveform and when the differential waveform

crosses its own voltage reference level. The closest single ended waveform edge to the differential waveform edge that falls

within the range limits is used for the measurement.

tCK(avg) (DDR)

tCK(avg) is the average clock period across a sliding 200-cycle window.

Where,

N=200 (configurable)

Measurement algorithms

566 4/5/6 Series MSO Help