Scalars Arguments

Scalar arguments are used to pass control type of information to the kernels. Scalar arguments can not be read back from the host. For each argument that is specified a corresponding control register is created to facilitate passing the argument from software to hardware.

  • Number of scalar kernel input arguments - Specifies the number of scalar input arguments to pass to the kernel. For each of the number specified, a table row is generated that allows customization of the argument name and argument type. There is no required minimum number of scalars and the maximum allowed by the wizard is 64.

Scalar Input Argument Definition

  • Argument name - The argument name is used in the generated Verilog control register module as an output signal. Each argument is assigned an ID value. This ID value is used to access the argument from the host software. The ID value assignments can be found on the summary page of this wizard. To ensure maximum compatibility, the argument name follows the same identifier rules as the kernel name.

  • Argument type - Specifies the the data type of the argument. This will affect the width of the control register in the generated Verilog module. The data types available are limited to the ones specified by the OpenCL version 2.0 specification. Data types that represent a bit width greater than 32 bits will require two write operations to the control registers.