Sigma-Delta Modulator
Purpose
Generate 2nd order sigma-delta modulator signals on digital outputs.
Description
RT Box 2, 3 and 4 each has 8 sigma-delta modulators, grouped in 2 units. Each unit can output a CLK and up to 4 DATA signals on digital outputs. While unit 1 can output signals to digital output channels 0 to 7, unit 2 can output to digital output channels 16 to 23. This channel mapping is optimized for the RT Box LaunchPad-Nucleo Interface.
The modulator input range is from -1 to 1, but for stability reasons, dynamic signals should be kept below 70-90% full scale. The minimum and maximum modulator input settings allow such clipping.
The modulator input is calculated as input*scale+offset.
Parameters
- Modulator unit
Select the desired modulator unit.
- Modulator frequency
The desired frequency of the modulator in hertz (Hz).
- Digital output channel for CLK
Index of the digital output channel used for the CLK signal. Can be left empty if a CLK signal is not needed.
- Digital output channel(s) for DATA
Index of the digital output channel used for the DATA signal. For vectorized output signals a vector of output channel indices must be specified. A modulator unit supports up to 4 DATA output elements. All 4 modulator channels run at the same modulator frequency.
- Offline simulation
Enables or disables data inspection in an offline simulation. If set to enabled, terminals are added to the subsystem for which code is generated. In an offline simulation the CLK and DATA output signals are available at these terminals. The block must be placed in the root schematic of the subsystem for which code is generated. If set to disabled, no such terminals will be added and the block can be used at any subsystem level.
- Scale
A scale factor for the modulator input signal.
- Offset
An offset for the scaled modulator input signal.
- Minimum modulator input
The lowest value that the modulator input signal can reach. Cannot be lower than -1.
- Maximum modulator input
The highest value that the modulator input signal can reach. Cannot exceed 1.