CORDIC co-processor

Enable hardware acceleration of trigonometric and hyperbolic mathematical functions

Since R2023b

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  • CORDIC Block

Libraries:
STM32 Microcontroller Blockset / STM32G4xx Based Boards
STM32 Microcontroller Blockset / STM32H7xx Based Boards
STM32 Microcontroller Blockset / STM32U5xx Based Boards

Description

The CORDIC co-processor block provides hardware acceleration of trigonometric and hyperbolic mathematical functions used in computationally intensive application to perform other tasks. The CORDIC co-processor block supports zero overhead mode.

Examples

Using CORDIC Co-Processor Block with DMA in STMicroelectronics STM32 Processor Based Boards

Using CORDIC Co-Processor Block with DMA in STMicroelectronics STM32 Processor Based Boards

Use and generate code for a CORDIC block in a Simulink® model for STMicroelectronics® NUCLEO-G431RB board to calculate SINE and COSINE values for given values of theta by using DMA.

Ports

Input

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Theta is an angle in radians divided by ᴨ (pi), [-1,1] for sin or cos function.

Theta is hyperbolic angle for hyperbolic functions [-0.559, 0.559]. For hyperbolic function the input values exceeding the range are saturated.

Dependencies

To enable this port, set Function to either sin, cos, sin and cos or sinh and cosh.

Data Types: fixdt(1,32,31) | int32

  • x - x coordinate

  • y - y coordinate

The range is [-1, 1].

Dependencies

To enable this port, set Function to either atan2, mod, atan2 and mod.

Data Types: fixdt(1,32,31) | int32

Output

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The block outputs the result of the selected function. Example, if you select function as sin and cos, the block outputs the result of sin and cos function.

Note

For hyperbolic function sinh or cosh, a gain of 2 must be added to the output.

Data Types: fixdt(1,32,31)

The block outputs CORDIC execution status.

  • 0 - Successful

  • 1 - Unsuccessful

Dependencies

To enable this port, select the Output status parameter.

Data Types: Boolean

The block outputs CORDIC execution function status.

The executed CORDIC function provides the following status:

  • 0 - cos

  • 1 - sin or sin and cos

  • 2 - atan2 or atan2 and mod

  • 3 - mod

  • 5 - cosh

  • 6 - sinh or sinh and cosh

Dependencies

To enable this port, set DMA mode to Read only and select the Execution function parameter.

Data Types: int32

The block outputs the executed iterations in the previous calculation.

The executed CORDIC iteration provides the following status:

  • 0 - cos

  • 1 - sin or sin and cos

  • 2 - atan2 or atan2 and mod

  • 3 - mod

  • 5 - cosh

  • 6 - sinh or sinh and cosh

Dependencies

To enable this port, set DMA mode to Read only and select the Execution iteration parameter.

Data Types: int32

The block outputs the executed array size in the previous calculation.

The executed CORDIC array size provides the following status:

  • 0 - cos

  • 1 - sin or sin and cos

  • 2 - atan2 or atan2 and mod

  • 3 - mod

  • 5 - cosh

  • 6 - sinh or sinh and cosh

Dependencies

To enable this port, set DMA mode to Read only and select the Execution array size parameter.

Data Types: int32

Parameters

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Select the trigonometric or hyperbolic function.

Programmatic Use

Block Parameter: Func

Select the iterations to improve the precision of the result.

Programmatic Use

Block Parameter: NumIters

Select DMA or Zero overhead as CORDIC mode.

  • Zero overhead - The data is written and read from the CORDIC co-processor individually.

  • DMA - The process of looping through the array of element is accomplished by DMA.

Programmatic Use

Block Parameter: CordicMode

Enables user to perform write and read operations of DMA from a single block.

  • Write only - perform write operation of DMA

  • Read - perform read operation of DMA

Dependencies

To enable this parameter, set the CORDIC mode to DMA.

Programmatic Use

Block Parameter: DMAmode

Specify the output data type for CORDIC co-processor.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: OutputDataType

Specify the input size for the CORDIC co-processor.

The user obtains a valid output when this parameter aligns with the input size of the write block.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: InpSize

When you select this parameter, the block configures Executed func output port. The port outputs the executed function in a previous step.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: ExecutedFunc

When you select this parameter, the block configures Executed iters output port. The port outputs the executed iterations in a previous step.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: ExecutedIterations

When you select this parameter, the block configures Executed array size output port. The port outputs the executed array size in a previous step.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: ExecutedArraySize

Specify how often (in seconds) the block reads the pin value. Enter a value greater than zero. When you specify this parameter as -1, Simulink determines the best sample time for the block based on the block context within the model.

Dependencies

To enable this parameter, set the DMA mode to Read only.

Programmatic Use

Block Parameter: SampleTime

Specify the DMA timeout in microseconds.

Programmatic Use

Block Parameter: TimeOut

Select to enable the preemption.

Programmatic Use

Block Parameter: EnablePreemption

When you select this parameter, the block configures Status output port. The Status port outputs the status of execution.

Programmatic Use

Block Parameter: EnableStatus

Version History

Introduced in R2023b

See Also