Register Channel

Timing model for transfer of register values

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Libraries:
SoC Blockset / Memory

Description

The Register Channel block provides a timing model for the transfer of register values between a processor and hardware logic. The register channel represents the datapath between a processor and a hardware IP via a common configuration bus. Configure the block to include one or more registers, and configure the direction for each register as write if the processor writes to it, or read if the processor reads from it.

Examples

Streaming Data from Hardware to Software

A systematic approach to design the data-path between hardware logic (FPGA) and embedded processor using SoC Blockset™.

• Open Script

Ports

Input

regN — Register input

scalar

Each register is assigned a port pair: an input and an output. You can configure the processor to be a writer or a reader. If the register is a read register, then the input comes from the hardware (HW) side. If the register is a write register, the input comes from the software (SW) side. By default, the Nth register port is named regN. You can change a register name by clicking Edit in the Registers parameter dialog box.

Dependencies

The number of input ports depends on the number of registers in the register table.

Output

regN — Register output

scalar

Each register is assigned a port pair: an input and an output. You can configure the processor to be a writer or a reader. If the register is configured as a read register, then the output goes to the software (SW) side. If the register is a write register, the output goes to the hardware (HW) side. By default, the Nth register port is named regN. You can change a register name by clicking Edit in the Registers parameter dialog box.

Dependencies

The number of output ports depends on the number of registers in the register table.

Parameters

Registers — Edit register name, direction, data type, dimension, and initial value

table

This parameter includes a table, where each of its lines corresponds to a register in your IP. Edit the table to add or edit a register configuration, up to 32 registers.

For each register, you can edit these values:

• Register Name – Specify the register name. This changes the input and output ports for this register.

• Direction – Choose write if the processor writes the register. Choose read if the processor reads the register.

• Data Type – Select the data type for the register. Supported data types are

  • single

  • int8

  • uint8

  • int16

  • uint16

  • int32

  • int64

  • uint32

  • uint64

  • boolean

  • fixdt(1,16,0)

  • fixdt(1,16,2^0,0)

  • fixed point

• Dimension – Select the vector size of the register. The default value is 1.

• Initial Value – Set the initial value of the register. The default value is 0. This value is applicable only when Direction is set to write.

Register write sample time — Sample time for register access

-1 (default) | two element vector

This sample time represents the clock period on the hardware side. Specify an offset time by entering a two-element vector for discrete blocks or configurable subsystems. The first element is the sample time, and the second element is the offset time. For example, an entry of [1.0 0.1] specifies a 1.0-second sample time with a 0.1-second offset. If no offset is specified, the default offset is zero.

When the value is -1, the block inherits its sample time value from the model.

Note

When the Direction of a register is set to Write, it implies that software is the writer and hardware is the reader, but Register write sample time determines the sample time of the signal on the hardware side.

Extended Capabilities

HDL Code Generation

Generate VHDL, Verilog and SystemVerilog code for FPGA and ASIC designs using HDL Coder™.

To automatically generate HDL code for your design, and execute on an SoC device, use the SoC Builder tool. See Use SoC Builder to Generate SoC Design.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced in R2019a

R2025a: Set initial value

Set an initial value for registers by editing the Initial Value field in the Registers table.