Stimulus
Set waveform generation method and number of symbols to simulate in SerDes model
Libraries:
SerDes Toolbox /
Utilities
Description
The Stimulus defines how to create the waveform and the number of symbols to simulate in a SerDes Toolbox™ model. You can directly specify a PAMn symbol pattern or define a binary to PAMn mapping scheme.
When you enable clock forwarding in the SerDes IBIS-AMI Manager dialog box, you can use the Stimulus block to generate clock times from an external clock times array or waveform.
Ports
Output
WaveOut — Output signal with specific PRBS pattern
vector
Output pattern with a specific PRBS pattern, specified as a vector.
Data Types: double
Parameters
Stimulus
Number of symbols — Length of stimulus pattern used for simulation
20000 (default) | positive real integer
Length of the stimulus pattern used for simulation, specified as a positive integer.
Programmatic Use
Block parameter:
NumberOfSymbols |
| Type: character vector |
| Values: positive real integer |
Default:
20000 |
Use recommended simulation stop time — Set recommended simulation stop time as simulation stop time
on (default) | off
Select to directly set the Recommended simulation stop time as the simulation stop time. By default, this option is selected.
Recommended simulation stop time defines the minimum time the simulation must run for meaningful results. It is calculated by multiplying the Sample Interval from the Configuration block with the Number of symbols.
Waveform creation method — Define how stimulus waveform is created
Random Symbols (default) | Serial PRBS | Symbol Pattern | Binary Pattern | Symbol Voltage Pattern | Sampled Voltage | Parallel PRBS
Define how the stimulus waveform is created:
Random Symbols— Randomly generate symbols directly from a uniform distribution.Serial PRBS— Define a binary sequence and map to a higher order modulation symbol. The mapping sequence depends on the modulation scheme defined in the Configuration block.Symbol Pattern— Directly define the symbol pattern as an integer from 0 to (Number of modulation levels – 1).Binary Pattern— Directly define the binary pattern and map to a higher order modulation symbol. The mapping sequence depends on the modulation scheme defined in the Configuration block.Symbol Voltage Pattern— Directly define the voltages of a symbol spaced pattern.Sampled Voltage— Directly define a sample interval spaced waveform.Parallel PRBS— Utilize multiple PRBS streams to form PAM4, PAM8 , PAM16, and PAM32 symbols. You can define up to 5 PRBS streams for PAM32. NRZ modulation scheme uses a single PRBS stream. Other modulation schemes use the random symbols waveform creation method.
Programmatic Use
Block parameter:
CreationMethod |
| Type: character vector |
Values:
Random Symbols | Serial PRBS
| Symbol Pattern | Binary
Pattern | Symbol Voltage Pattern |
Sampled Voltage | Parallel
PRBS |
Default:
Random Symbols |
Random symbols seed — Seed for generating random symbol waveform
1431655765 (default) | positive real scalar
Seed for generating the random symbol waveform, specified as a positive real scalar.
Dependencies
To enable this parameter, set Waveform creation method parameter to
Random Symbols.
Programmatic Use
Block parameter:
soPAMnSeed |
| Type: character vector |
| Values: positive real scalar |
Default:
1431655765 |
PRBS order — Order of pseudorandom binary sequence
11 (default) | 7 | 9 | 13 | 15 | 20 | 23 | 31 | 47
Order of the pseudorandom binary sequence while creating the stimulus waveform using serial PRBS or parallel PRBS method.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Serial PRBS or
Parallel PRBS.
Programmatic Use
Block parameter:
PRBS |
| Type: character vector |
Values:
7 | 9 |
11 | 13 |
15 | 20 |
23 | 31 |
47 |
Default:
11 |
PRBS seed — Seed of pseudorandom binary sequence
1 (default) | integer in the range [1, 2Order-1]
Seed for generating the pseudorandom binary sequence, specified as an integer in the range of [1, 2Order-1].
Dependencies
To enable this parameter, set Waveform creation
method parameter to Serial PRBS or
Parallel PRBS.
Programmatic Use
Block parameter:
PRBSSeed |
| Type: character vector |
| Values: integer in the range [1, 2Order-1] |
Default:
1 |
Reverse PRBS in time — Reverse PRBS in time by reversing tap positions of characteristic polynomial
off (default) | on
Reverse the PRBS in time (along x-axis) by reversing the tap positions of the characteristic polynomial.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Serial PRBS or
Parallel PRBS.
Invert PRBS in voltage — Invert PRBS in voltage by flipping the values of 0 and 1
off (default) | on
Invert the PRBS in voltage (along y-axis) by converting 0s to 1s and 1s to 0s.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Serial PRBS or
Parallel PRBS.
Symbol pattern — Vector of symbol integers spaced at symbol time interval
[0 0 1 0 0 1 1 0 1 0 1 1 1 1 0] (default) | vector with element values in the range [0, (Number of modulation
levels-1)]
Vector of the symbol integers spaced at the symbol time interval. The elements of the vector must have values in the range [0, (Number of modulation levels-1)]
Dependencies
To enable this parameter, set Waveform creation
method parameter to Symbol
Pattern.
Programmatic Use
Block parameter:
SymbolPattern |
| Type: character vector |
| Values: vector with element values in the range [0, (Number of modulation levels-1)] |
Default:
[0 0 1 0 0 1 1 0 1 0 1 1 1 1 0] |
Binary pattern — Vector of 1s and 0s spaced at sample time interval
[0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1
0 1 0] (default) | vector with binary elements
Vector of binary elements (1s and 0s) spaced at the symbol time interval.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Binary
Pattern.
Programmatic Use
Block parameter:
BinaryPattern |
| Type: character vector |
| Values: vector with binary elements |
Default:
[0 0 0 1 0 0 1 0 1 1 0 0 1 1 1 1 1 0 0 0 1 1 0 1 1 1 0 1 0 1
0] |
Symbol voltage pattern — Vector of symbol voltages spaced at symbol time interval
1/2*[1 1 1 1 -1 -1 -1 -1] (default) | vector with decimal values
Vector of symbol voltages spaced at the symbol time interval.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Symbol Voltage
Pattern.
Programmatic Use
Block parameter:
SymbolVoltageDataPattern |
| Type: character vector |
| Values: vector with decimal values |
Default:
1/2*[1 1 1 1 -1 -1 -1 -1] |
Sampled voltage pattern — Vector of voltages spaced at sample interval
[zeros(1,(SymbolTime/SampleInterval)),ones(1,(SymbolTime/SampleInterval))]-0.5 (default) | real valued vector
Vector of voltages spaced at the sample interval.
Dependencies
To enable this parameter, set Waveform creation
method parameter to Sampled
Voltage.
Programmatic Use
Block parameter:
CustomStimulus |
| Type: character vector |
| Values: real valued vector |
Default:
[zeros(1,(SymbolTime/SampleInterval)),ones(1,(SymbolTime/SampleInterval))]-0.5 |
Sub symbol time delay (s) — Delay stimulus waveform by modulo symbol time
0 (default) | nonnegative real scalar
Delay the stimulus waveform by modulo symbol time to slightly shift the eye diagram or recovered clock phase.
The modulo operation finds the remainder after division.
Programmatic Use
Block parameter:
soDelay |
| Type: character vector |
| Values: nonnegative real scalar |
Default:
0 |
Clock Forwarding
Change in IBIS-AMI Manager — Modify Rx_Use_Clock_Input reserved AMI parameter
button
Modify the Rx_Use_Clock_Input reserved AMI parameter using the SerDes IBIS-AMI Manager dialog box. You can change the parameter in the AMI-Rx tab of the SerDes IBIS-AMI Manager.
You can use either a waveform or clock times data to forward as a clock. The Current State parameter shows what type of data you are forwarding.
Generate Clock or Strobe Waveform — Generate clock or strobe waveform from waveform parameters
off (default) | on
Generate a clock or strobe waveform from the specified waveform parameters.
You can define a clock pattern with delay. Alternately, you can define a strobe pattern with delay, burst length, idle length, pre-amble, and post-amble.
You can also define the transmitter jitter parameters to include when generating the clock or strobe pattern.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave.
Use External Waveform or Clock Times Array — Use external waveform to forward
on (default) | off
Use an external clock to forward. You can define the external clock in the base or model workspace and use the Waveform Name parameter to point to it.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave.
Include Analog Channel Model in clock waveform — Include analog channel model in clock waveform
on (default) | off
Select to include the analog channel model in the clock waveform.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave.
Clock Pattern — Forwarding clock pattern
off (default) | on
Select to generate a forwarding clock pattern. You can also define the clock delay and include transmitter jitter.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Strobe Pattern — Forwarding strobe pattern
on (default) | off
Select to generate a forwarding strobe pattern. You can also define the strobe delay, burst length, idle length, pre-amble, post-amble, and include transmitter jitter.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Delay (s) — Delay forwarding clock
0 (default) | nonnegative real scalar
Delay the forwarding clock, specified as a nonnegative real scalar.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_Delay |
| Type: character vector |
| Values: nonnegative real scalar |
Default:
0 |
Burst Length — Number of symbols between strobe burst pattern
16 (default) | nonnegative scalar integer
Number of symbols between the strobe burst pattern or clock pattern, specified as a nonnegative scalar integer.
Programmatic Use
Block parameter:
CF_BurstLen |
| Type: character vector |
| Values: nonnegative scalar integer |
Default:
0 |
Idle Length — Number of symbol between bursts
8 (default) | nonnegative scalar integer
Number of symbol between bursts, specified as a nonnegative scalar integer.
Programmatic Use
Block parameter:
CF_IdleLen |
| Type: character vector |
| Values: nonnegative scalar integer |
Default:
0 |
Preamble — Number of additional clock cycles added to beginning of each burst
2 (default) | nonnegative scalar integer
Number of additional clock cycles added to the beginning of each burst, specified as a nonnegative scalar integer. A clock cycle consists of two symbols.
Programmatic Use
Block parameter:
CF_Preamble |
| Type: character vector |
| Values: nonnegative scalar integer |
Default:
2 |
Postamble — Number of additional clock cycles added to end of each burst
0 (default) | nonnegative scalar integer
Number of additional clock cycles added to the end of each burst, specified as a nonnegative scalar integer. A clock cycle consists of two symbols.
Programmatic Use
Block parameter:
CF_Postamble |
| Type: character vector |
| Values: nonnegative scalar integer |
Default:
0 |
Include Transmitter Jitter — Include transmitter jitter in forwarded clock
on (default) | off
Select to include transmitter jitter in the forwarded clock.
Tx_Dj (UI) — Transmitter deterministic jitter
0 (default) | scalar in the range [0 1]
Transmitter deterministic jitter, specified as a scalar in the range [0 1]. It is defined as half of the peak-to-peak worst case variation.
Deterministic jitter is usually modeled as bounded uniform jitter. It is also known as uncorrelated bounded high probability jitter.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_TxDj |
| Type: character vector |
| Values: scalar in the range [0 1] |
Default:
0 |
Tx_Rj (UI) — Transmitter random jitter
0 (default) | scalar in the range [0 1]
Transmitter random jitter, specified as a scalar in the range [0 1]. It is defined as the standard deviation of a white Gaussian phase noise process.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_TxRj |
| Type: character vector |
| Values: scalar in the range [0 1] |
Default:
0 |
Tx_DCD (UI) — Transmitter duty cycle distortion
0 (default) | scalar in the range [0 1]
Transmitter duty cycle distortion, specified as a scalar in the range [0 1].It is defined as half of the peak-to-peak difference in symbol duration between one symbol and the next.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_TxDCD |
| Type: character vector |
| Values: scalar in the range [0 1] |
Default:
0 |
Tx_Sj (UI) — Transmitter sinusoidal jitter
0 (default) | scalar in the range [0 1]
Transmitter sinusoidal jitter, specified as a scalar in the range [0 1]. It is defined as half of the peak-to-peak variation of sinusoidal phase noise amplitude.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_Sj |
| Type: character vector |
| Values: scalar in the range [0 1] |
Default:
0 |
Tx_Sj_Frequency (Hz) — Transmitter sinusoidal jitter frequency
0 (default) | scalar in the range [0 100e9]
Frequency of the transmitter sinusoidal jitter, specified as a scalar in the range [0 100e9].
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Generate Clock or Strobe
Waveform option.
Programmatic Use
Block parameter:
CF_TxSjFreq |
| Type: character vector |
| Values: scalar in the range [0 100e9] |
Default:
0 |
Waveform Name — Name of waveform parameter in workspace
defaultClockWave (default) | character string
Name of the waveform parameter in the base or model workspace that contains the external waveform data.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Use External Waveform or
Clock Times Array option.
Programmatic Use
Block parameter:
CF_WaveformName |
| Type: character vector |
| Values: character string |
Default:
0 |
Waveform Delay (s) — Delay forwarding clock
0 (default) | nonnegative scalar integer
Delay the forwarding clock, specified as a nonnegative scalar integer.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Wave and select the Use External Waveform or
Clock Times Array option.
Programmatic Use
Block parameter:
CF_WaveDelay |
| Type: character vector |
| Values: nonnegative scalar integer |
Default:
0 |
Clock Times Name — Name of clock times parameter in workspace
defaultClockTimes (default) | character string
Name of the clock times parameter in the base or model workspace that contains the external clock times data.
Dependencies
To enable this parameter, select Current value of
Rx_Use_Clock_Input parameter to
Time.
Programmatic Use
Block parameter:
CF_ClockTimesName |
| Type: character vector |
| Values: character string |
Default:
0 |
Version History
Introduced in R2019aR2023b: Clock Forwarding
Use the Clock Forwarding tab in the Stimulus block to generate clock stimulus patterns.
See Also
Analog Channel | Configuration | DFEClkFwd | serdes.Stimulus
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