CDR

Input baseband signal. The input to the CDR must be applied as one sample at a time and not as a vector.

Data Types: double

Determine the CDR order to enable phase and frequency tracking.

Programmatic Use

Block parameter: CDRMode

Type: character vector

Values: 1st order | 2nd order

Default: 1st order

Clock phase detector option used in the clock data recovery. You can choose between bang-bang (Alexander) or baud-rate type-A (Mueller-Muller).

Programmatic Use

Block parameter: PhaseDetector

Type: character vector

Values: BangBang | BaudRateTypeA

Default: BangBang

Clock phase offset, specified as a real scalar in the range [-0.5,0.5] in fraction of symbol time. Phase Offset is used to manually shift clock probability distribution function (PDF) for better bit error rate (BER).

Programmatic Use

Block parameter: PhaseOffset

Type: character vector

Values: real scalar in the range [-0.5,0.5]

Default: 0

Data Types: double

Reference clock offset impairment, specified as a real scalar in the range [0, 300] in parts per million (ppm). Reference offset (ppm) is the deviation between transmitter oscillator frequency and receiver oscillator frequency.

Programmatic Use

Block parameter: ReferenceOffset

Type: character vector

Values: real scalar in the range [0, 300]

Default: 0

Data Types: double

Early or late CDR count threshold to trigger a phase update, specified as a unitless real positive integer ≥5. Increasing the value of Early/late count threshold provides a more stable output clock phase at the expense of convergence speed. Because the bit decisions are made at the clock phase output, a more stable clock phase has a better bit error rate (BER).

Early/late count threshold also controls the bandwidth of the CDR.

Programmatic Use

Block parameter: Count

Type: character vector

Values: real positive integer ≥5

Default: 16

Data Types: double

Clock phase resolution, specified as a real scalar in fraction of symbol time. Step (symbol time) is the inverse of the number of phase adjustments in CDR.

Programmatic Use

Block parameter: Step

Type: character vector

Values: real scalar

Default: 0.0078

Data Types: double

Internal gain for the frequency tracking loop, specified as a nonnegative real scalar.

Dependencies

To enable this parameter, set the CDR Mode to 2nd order.

Programmatic Use

Block parameter: FrequencyStep

Type: character vector

Values: nonnegative real scalar

Default: 0.00048828125

Data Types: double

Once every Frequency tracking update symbols, update the system phase rotator clock with the frequency estimate.

Dependencies

To enable this parameter, set the CDR Mode to 2nd order.

Programmatic Use

Block parameter: FrequencyCount

Type: character vector

Values: nonnegative real scalar

Default: 16

Data Types: double

To help frequency tracking loop lock early in a simulation, the initial Frequency tracking gain starts at a high value of 1/(2*Frequency tracking update). Then the Frequency tracking gain gradually reduces to the specified value by roughly Frequency step ramp symbol times.

Dependencies

To enable this parameter, set the CDR Mode to 2nd order.

Programmatic Use

Block parameter: FrequencyStepRamp

Type: character vector

Values: nonnegative real scalar

Default: 3000

Data Types: double

Sampling latch metastability voltage, specified as a real scalar in volts. If the data sample voltage lies within the region (±Sensitivity (V)), there is a 50% probability of bit error.

Programmatic Use

Block parameter: Sensitivity

Type: character vector

Values: real scalar

Default: 0

Data Types: double

Select to include Phase Offset as a parameter in the IBIS-AMI file. If you deselect Phase Offset, it is removed from the AMI files, effectively hard-coding Phase Offset to its current value.

Select to include Reference offset as a parameter in the IBIS-AMI file. If you deselect Reference offset, it is removed from the AMI files, effectively hard-coding Reference offset to its current value.