The Meas module supports jitter & timing measurements required for high speed digital signal integrity. It requires either a clock input, a data input or both depending upon measurements selected. The clock and data inputs double as IN1 and IN2 respectively for multi-channel measurements like channel to channel skew.

Following are the available measurements:

Clock: Period, frequency, positive width, negative width, positive duty cycle, negative duty cycle, time interval error, cycle-cycle jitter, N-cycle jitter, cycle-cycle positive width, cycle-cycle negative width, cycle-cycle positive duty cycle, cycle-cycle negative duty cycle, rise time, fall time, rise slew rate, fall slew rate.
Amplitude: cycle max, cycle min, cycle peak-peak, cycle mean, cycle RMS.
Data: Period, frequency, time interval error, rise time, fall time, rise slew rate, fall slew rate
Multi-channel: Setup time, hold time, channel-channel skew, channel-channel crossover voltage

The Meas module supports two graphical user interfaces. One for configuring inputs and one for configuring outputs. Below is a description of both the interfaces.

Graphical Interface

You can use either individual measurement symbols or all in one measurement symbol. If you want to perform more than one measurement on the same signal, then you should use the all in one measurement, since it calculates multiple measurements faster.

Input Ports

Dt (Data In)

Connect the data signal to the Dt input. This signal is required only for data measurements and need not be connected for clock only measurements.
Ck (Clock In)

Connect the clock signal to the Ck input. This signal is required for clock and some data measurements.
Ctl (Control In)

Connect the control signal to the Ctl input. This signal is only required for gated measurements.

Clock Measurements

Data Measurements

Multi-Channel Measurements

Schematic Symbol

Settings: Measurement Inputs

To configure Meas Inputs, select the active edge and enter high, mid & low thresholds, and hysteresis for the channels being used. If the falling edge thresholds are different from rising edge thresholds, then you can specify the offsets for falling edge thresholds. If you are using measurements which only use mid threshold, then you don't need to configure low and high thresholds. Similarly, if you have selected measurements which only use low and high thresholds, then you don't need to enter mid threshold.

Edge [Dropdown List]

Select the active edge or level for the selected channel. The options change as per the selected channel and are explained below:

Clock/IN1:
Rise: Select the Rise Option if the data is latched on the rising clock edge.
Fall: Select the Fall Option if the data is latched on the falling clock edge.
Both: Select the Both Option if the data is latched on both rising & falling edges of the clock edge. This option is useful for making measurements on a DDR (Dual Data Rate) system.
Data/IN2:
Rising: Select the Rise Option to make measurements only on the rising data edge.
Falling: Select the Fall Option to make measurements only on the falling data edge.
Both: Select the Both Option to make measurements on the both rising and falling data edges.
Control:
OFF: Select the Off Option to turn control channel OFF.
Low: Select the Low Option if the measurement inputs are valid whenever control channel is low.
High: Select the High Option if the measurement inputs are valid whenever control channel is high.

H [Textbox]

Enter the high level threshold for the selected channel in the H Textbox. The high level threshold is used along with the low threshold for edge-time and edge-rate measurements:

M [Textbox]

Enter the mid level threshold for the selected channel in the M Textbox. The mid level threshold is used for all edge to edge measurements.

L [Textbox]

Enter the low level threshold for the selected channel in the L Textbox. The low level threshold is used along with the high threshold for edge-time and edge-rate measurements:

Hysteresis [Textbox]

Enter the hysteresis for the selected channel in the Hysteresis Textbox. The hysteresis is an important setting and should be larger than the peak noise value, and should be lower than the minimum peak signal. This setting doesn't affect the threshold levels and is just used to isolate noise.

More [Checkbox]

Marking the More Checkbox shows more advanced options.

Falling Edge Thr Offsets

Enter a value in the High, Mid or Low Textboxes if the falling edge thresholds are different from the rising edge thresholds. This is the case when the device input buffers have asymmetric rising & falling input thresholds.

High [Textbox]
Enter the difference between high level falling threshold and high level rising threshold in the High Textbox.
For example, say,
    High level rising threshold = 2.1V &
    High level falling threshold = 1.9V
Then, enter the following values:
    H = 2.1, High = -0.2
Mid [Textbox]
Enter the difference between mid level falling threshold and mid level rising threshold in the Mid Textbox.
For example, say,
    Mid level rising threshold = 1.7V &
    Mid level falling threshold = 1.3V
Then, enter the following values:
    M = 1.7, Mid = -0.4
Low [Textbox]
Enter the difference between low level falling threshold and low level rising threshold in the Low Textbox.
For example, say,
    Low level rising threshold = 1.1V &
    Low level falling threshold = 0.9V
Then, enter the following values:
    L = 1.1, Low = -0.2

Settings: Measurement Outputs

Most of the measurements are not required to be configured.

Measurements [List]

Select a measurement from the Measurement List that you want to configure. Most of the measurements are not required to be configured except JNC (Jitter N-Cycle).

Valid Range

Enter valid range value if you want to limit the measurement results. This is useful in making measurements on non-contiguous clocks.

Max (s) [Textbox]
Enter maximum limit for the selected measurement in the Max Textbox, or leave blank for none. Measurement values above this limit are not reported. Example: You want to measure period of a non-contiguous clock. Let's assume that the average period is 100 nS with a variation of 9 nS. If you enter Max = 110n, the software will reject values above 110 nS and report clock period accurately.
Min (s) [Textbox]
Enter minimum limit for the selected measurement in the Min Textbox, or leave blank for none. Measurement values below this limit are not reported. Example: You want to measure frequency of a non-contiguous clock. Let's assume that the average frequency is 100 MHz with a variation of 9 MHz. If you enter Min = 90M, the software will reject values below 90 MHz and report clock frequency accurately.

Start Cycle [Textbox] (CkJNC Only)

Enter the first cycle to start measurement from in the Start Cycle Textbox. This field is applicable only for Clock Jitter N-Cycle (JNC).

N Cycles [Textbox] (CkJNC Only)

Enter N for N-Cycle jitter measurement in the N Cycles Textbox. This field is applicable only for Clock Jitter N-Cycle (JNC).

Meas: Timing & Jitter Measurement & Analysis

Graphical Interface

Input Ports

Dt (Data In)

Ck (Clock In)

Ctl (Control In)