excel2pyral 1.2.7

Convert Excel register specifications to PyUVM RAL models via SystemRDL

excel2pyral Converter

A comprehensive tool for converting Excel register specifications into Python PyUVM Register Abstraction Layer (RAL) models via SystemRDL intermediate representation.

⚠️ Note:
excel2pyral is currently under active development. Features and interfaces may change, and some functionalities might be incomplete or unstable.
Please use it carefully and report any issues or feedback to help improve the project. 🙏

🚀 Features

• Excel to PyUVM RAL: Convert Excel register specs directly to Python PyUVM RAL models
• SystemRDL Generation: Generate standalone SystemRDL files from Excel specifications
• SV Register Interface Generation: Auto-generate regif_pkg.sv (typedef structs) and regif_{name}_top.sv (glue module) from Excel or RDL — triggered automatically by genrdl and pyral --keep-rdl, or standalone via genregif
• Built-in GUI Editor: Interactive Excel editor for viewing and modifying register specifications
• Selective Submodule Processing: Choose specific submodules to process with -s/--submodules flag
• Flexible Top-Level Naming: Automatic or custom naming with priority-based logic
• Comprehensive Validation: Early error detection with hierarchy and sheet consistency checks
• Proper UVM Structure: Generates hierarchical RAL models matching industry standards
• SystemRDL Integration: Uses SystemRDL as intermediate representation for accuracy
• Built-in Validation: Automatic validation through SystemRDL compiler ensures correctness of register descriptions
• Submodule Support: Handles complex hierarchical designs with multiple IP blocks
• Field-Level Detail: Supports register fields with access types, reset values, descriptions
• Debug Support: Comprehensive logging and intermediate file preservation options
• Flexible Output: Choose between PyUVM RAL generation or standalone SystemRDL output

📁 Project Structure

excel2pyral/                      # Root project directory
├── README.md                     # This file
├── requirements.txt              # required python package list
├── pyproject.toml                # Build system and configuration for your Python project
├── excel2pyral/                  # Main Python package
│   ├── __init__.py               # Package initialization
│   ├── excel_importer.py         # Excel to SystemRDL converter
│   ├── systemrdl_compiler.py     # SystemRDL compiler wrapper
│   ├── pyuvm_generator.py        # PyUVM RAL generator
│   ├── sv_regif_generator.py     # SV register interface generator (regif_pkg + top)
│   └── main.py                   # Main converter logic
├── docs/                         # Documentation
|   ├── README_api.md             # README file for API
|   └── genregif_README.md        # README for genregif SV interface generator
├── examples/                     # Example files
|   ├── mychip.xlsx               # Simple example input Excel file
|   ├── mychip.rdl                # Generated SystemRDL file for mychip
|   ├── mychip_ral.py             # Generated PyUVM RAL model for mychip
|   ├── PROJECT_TEST.xlsx         # Complex example with multiple modules
|   ├── PROJECT_TEST.rdl          # Generated SystemRDL for complex example
|   └── PROJECT_TEST_ral.py       # Generated PyUVM RAL for complex example
└── setup.py                      # Package installation

📋 Table of Contents

• Features

• Project Structure

• Available Commands

  • pyral Command
  • genrdl Command
  • genregif Command

• Installation

  • Prerequisites
  • Install Package

• Command Line Options

  • Common Options
  • Additional Options for pyral
  • genregif Options

• Excel File Format

  • Required Sheets
  • Column Descriptions
  • Field Bits Format
  • Access Permission Values

• Quick Start

  • Prepare Excel File
  • Automatic SystemRDL Validation
  • Run Conversion
  • Use Generated PyUVM RAL

• Python API

  • ExcelToPyRALConverter Class
  • Individual Components

• Generated PyUVM Structure

  • Register Classes
  • Block Classes

• Best Practices

  • Excel Organization
  • Module Design
  • PyUVM Integration
  • Development Workflow

• Troubleshooting

  • Common Issues
  • Debug Mode
  • Validation

• Contributing

• License

• Acknowledgments

� Available Commands

The package provides two main commands:

1. pyral Command

Converts Excel register specifications to PyUVM RAL models with optional SystemRDL generation.

# Basic conversion to PyUVM RAL
pyral registers.xlsx

# Edit Excel file in GUI editor
pyral registers.xlsx --edit
pyral registers.xlsx -e

# Keep intermediate SystemRDL file
pyral registers.xlsx --keep-rdl

# Process only specific submodules
pyral registers.xlsx -s CPU_Core Memory_Ctrl

# Specify custom names
pyral registers.xlsx --top-name chip_top --package-name chip_ral_pkg

# Custom output directory and keep SystemRDL
pyral chip_spec.xlsx --output results/ --keep-rdl

# Custom sheet names (updated parameter)
pyral design.xlsx --hierarchy-sheet "Hierarchy" --default-sheet "Properties"

# Process selective submodules with custom top name
pyral my_chip.xlsx -s GPIO UART -t custom_chip_top --package-name custom_ral

2. genrdl Command

Generates only the SystemRDL file from Excel specifications.

# Basic SystemRDL generation
genrdl registers.xlsx

# Edit Excel file in GUI editor
genrdl registers.xlsx --edit
genrdl registers.xlsx -e

# Custom output directory
genrdl registers.xlsx -o output/

# Custom top-level name
genrdl registers.xlsx --top-name chip_top

# Process only specific submodules  
genrdl registers.xlsx -s CPU_Core UART_Module

# Custom top name with selective processing
genrdl registers.xlsx -s Memory_Ctrl --top-name memory_subsystem

# Verbose output
genrdl registers.xlsx -v

Note: genrdl automatically generates regif_pkg.sv and regif_{name}_top.sv alongside the SystemRDL file. When used with -s, each submodule gets its own regif_{submodule}_pkg.sv.

3. genregif Command

Generates SystemVerilog register interface files directly from an existing .rdl file. Use this when you already have a compiled SystemRDL file and need to (re)generate the SV interface.

# Basic SV register interface generation
genregif rdl_datacap.rdl

# Custom output directory
genregif rdl_datacap.rdl -o rtl/

# Override struct/module prefix
genregif rdl_datacap.rdl --prefix dc

# Override SV package name
genregif rdl_datacap.rdl --sv-pkg snap_regif_pkg

# Override top module name
genregif rdl_datacap.rdl --module-name regif_dc_top

# Override register data width (if not declared in RDL)
genregif rdl_datacap.rdl --data-width 64

# Verbose output
genregif rdl_datacap.rdl -v

�🔧 Installation

Prerequisites

# Required dependencies
pip install systemrdl-compiler
pip install pyuvm
pip install pandas
pip install openpyxl

Install Package

# Clone the repository
git clone https://github.com/SanCodex/excel2pyral.git
cd excel2pyral

# Install in development mode
pip install -e .

🎯 Command Line Options

pyral Command

usage: pyral [-h] [--version] [-o OUTPUT] [-r] [-t TOP_NAME] [--package-name PACKAGE_NAME]
            [--hierarchy-sheet HIERARCHY_SHEET] [--default-sheet DEFAULT_SHEET] 
            [-s SUBMODULES [SUBMODULES ...]] [-e] [-v] [-q]
            excel_file

Convert Excel register specifications to PyUVM RAL models

genrdl Command

usage: genrdl [-h] [--version] [-o OUTPUT] [-t TOP_NAME] 
             [--hierarchy-sheet HIERARCHY_SHEET] [--default-sheet DEFAULT_SHEET]
             [-s SUBMODULES [SUBMODULES ...]] [-e] [-v] [-q]
             excel_file

Convert Excel register specifications to SystemRDL

Common Options for Both Commands

Option	Description	Default
-e, --edit	Open Excel file in GUI editor before conversion	False
-o, --output	Output directory	output
-t, --top-name	Override top-level addrmap name (Priority 1)	See Top Name Logic
--hierarchy-sheet	Name of submodule hierarchy sheet	Hierarchy
--default-sheet	Name of default properties sheet	default
-s, --submodules	Specific submodule sheets to process (enables selective processing)	All sheets
-v, --verbose	Enable verbose output	False
-q, --quiet	Suppress all output except errors	False

Top Name Logic (Priority Order)

The top-level addrmap name is determined using the following priority order:

1. If -t/--top-name is specified: Use the provided name
2. If -s/--submodules is used: Use {submodule_names}_top format
3. If neither: Use Excel filename (without extension)

Examples:

• pyral chip.xlsx -t CustomChip → CustomChip.rdl
• pyral chip.xlsx -s CPU GPIO → CPU_GPIO_top.rdl
• pyral chip.xlsx → chip.rdl

Additional Options for pyral Command

Option	Description	Default
-r, --keep-rdl	Keep intermediate SystemRDL file (also triggers SV regif generation)	False
--package-name	Name for UVM package	{top_name}_ral

genregif Command Options

usage: genregif [-h] [--version] [-o OUTPUT] [--prefix PREFIX]
               [--module-name MODULE_NAME] [--sv-pkg SV_PKG]
               [--data-width DATA_WIDTH] [-v] [-q]
               rdl_file

Option	Default	Description
rdl_file	(required)	Path to the SystemRDL (.rdl) input file
-o, --output	output	Output directory for generated .sv files
--prefix	auto (from addrmap name)	Struct/module name prefix (e.g. datacap)
--module-name	regif_{prefix}_top	Override generated top module name
--sv-pkg	regif_pkg	Override SV package name
--data-width	auto (from RDL regwidth)	Register data width in bits
-v, --verbose	—	Enable verbose output
-q, --quiet	—	Suppress all output except errors

Prefix auto-detection strips common RDL prefixes from the addrmap name:

Addrmap name	Auto prefix
rdl_datacap	datacap
reg_uart	uart
my_module	my_module (no strip)

⚡ Quick Start

Excel GUI Editor

Both pyral and genrdl commands include a built-in GUI editor for Excel files. This feature allows you to:

• View and edit Excel register specifications in a user-friendly interface
• Quickly modify register definitions, offsets, and field properties
• Validate your changes before conversion
• Save changes directly to the Excel file

Using the Excel Editor:

# Edit Excel file in GUI editor
pyral registers.xlsx --edit

# Edit Excel file in GUI editor
genrdl registers.xlsx -e

# Short form works with both commands
pyral chip_spec.xlsx -e
genrdl design.xlsx -e

Features:

• Browse all sheets in your Excel file
• Select and view register definitions
• Edit cell values directly in the GUI
• Save changes and close to proceed with conversion
• Cancel to abort without conversion

Note: The editor opens in a Tkinter GUI window, so ensure you have a display available. After closing the editor:

• If you saved changes, conversion proceeds with the updated file
• If you cancelled or closed without saving, the conversion is aborted

📊 Excel File Format

Required Sheets

1. "Hierarchy" Sheet (Required for hierarchical designs)

Defines the top-level module hierarchy:

Column	Description	Example
Submodule Name	Name of the module type/class	GPIO, UART, SPI
Instances	Unique instance name	gpio0, uart_primary
Base Addresses	Hexadecimal base address	0x1000, 0x2000

Note: The hierarchy sheet name can be customized using --hierarchy-sheet parameter.

2. Module Type Sheets (One per module type)

Define registers and fields for each module type:

Column	Description	Example
Register Name	Name of the register	CONTROL_REG
Offset	Offset within module	0x0, 0x4
Width	Register Width	32, 64
Reset Value	Reset value (hex/decimal)	0, 0x5A
Field Name	Name of the register field	ENABLE, MODE
Field Bits	Field bit positions	[0:0], [7:4]
Field Descripton	Description of field bits	Start txn UART
SW Access	Access type	rw
HW Access	Hardware access	r
Behaviour	SystemRDL field property	onwrite=woclr, onwrite=woset

3. "default" Sheet (Optional)

Global default properties:

Property	Value	Description
regwidth	32	Default register width
accesswidth	32	Default access width
addressing	regalign	Address alignment

Column Value Inheritance

When a register has multiple fields, you can leave certain column values empty and they will be inherited from the previous row. This applies to:

• Register Name
• Offset
• Width
• Reset Value

For example, in the UART sheet below, the second field 'START' of RESET_REG inherits the register properties from the first row. This reduces redundancy and makes the spreadsheet more maintainable.

Column Descriptions

Required Columns:

• Register Name: Name of the register
• Offset: Register offset address (hex format: 0x...)
• Field Name: Name of the register field
• Field Bits: Bit range in format [msb:lsb], [bit], or width number

Optional Columns:

• Field Description: Description of the field's functionality
• SW Access: Software access permissions (e.g., rw, r, w, rw1c)
• HW Access: Hardware access permissions (e.g., r, w, rw)
• Reset Value: Field reset value (hex format)
• Behaviour: Additional field behaviors using SystemRDL property assignments. Examples:
  • onwrite=woclr - Write one to clear behavior
  • onwrite=woset - Write one to set behavior

Field Bits Format Support:

• Range format: [7:0] - 8-bit field from bit 7 to 0
• Single bit: [3] - Single bit field at position 3
• Width only: 8 - 8-bit field (position auto-assigned)

Access Permission Values:

• Software (SW) Access:

  • rw: Read-Write
  • r: Read-only
  • w: Write-only
  • rw1c: Read-Write 1 to Clear
  • Other standard SystemRDL access types

• Hardware (HW) Access:

  • r: Read-only
  • w: Write-only
  • rw: Read-Write
  • Other standard SystemRDL access types

Selective Submodule Processing

You can process only specific submodules instead of all sheets using the -s/--submodules flag:

# Process only GPIO and UART submodules
pyral registers.xlsx -s GPIO UART

# Process single submodule with custom top name  
pyral chip.xlsx -s Memory_Controller -t memory_top

# Generate SystemRDL for specific submodules
genrdl design.xlsx -s CPU_Core ALU_Unit

Benefits of Selective Processing:

• ✅ Faster generation for large designs
• ✅ Focus on specific subsystems during development
• ✅ Reduced output complexity for testing
• ✅ Automatic top name generation ({submodule}_top)

Validation: The tool validates that:

• All specified submodules exist in the hierarchy sheet
• All specified submodule sheets exist in the Excel file
• Consistent processing between hierarchy and register definitions

1. Prepare Your Excel File

Create an Excel file with register specifications:

Sheet: "Hierarchy"

Submodule Name	Instances	Base Addresses
GPIO	gpio0,gpio1	0x1000,0x1100
UART	uart0,uart1	0x2000,0x3000

Sheet: "default" (Optional)

SW Access	HW Access	Access Width	Reg Width
rw	r	32	32

The default sheet provides global default values that apply to all registers unless overridden.

Sheet: "GPIO"

Register Name	Offset	Width	Reset Value	Field Name	Field Bits	Field Description	SW Access	HW Access	Behaviour
CTRL_REG	0x0	32	0x0	ENABLE	[0:0]	Enable GPIO	rw	r	onwrite=woclr
				MODE	[3:1]	Mode Select	rw	r	onwrite=woclr
STATUS_REG	0x4	32	0x0	INT_STATUS	[0:0]	Interrupt Status	rw1c	r	onwrite=woclr

Sheet: "UART"

Register Name	Offset	Width	Reset Value	Field Name	Field Bits	Field Description	SW Access	HW Access	Behaviour
RESET_REG	0x8	32	0x0	PAUSE	[0:0]	Pause txn UART	rw	r	onwrite=woclr
				START	[3:1]	Start txn UART	rw	r
STOP_REG	0x16	32	0x0	END	[0:0]	Stop txn UART	rw	r	onwrite=woclr

2. Automatic SystemRDL Validation

One of the key features of excel2pyral is its built-in validation through the SystemRDL compiler. Both pyral and genrdl commands perform this validation automatically. During conversion, your register descriptions go through rigorous validation:

For pyral command:

Excel File → SystemRDL Generation → SystemRDL Compiler Validation → PyUVM RAL

With --keep-rdl:

Excel File → SystemRDL Generation → SystemRDL Compiler Validation → PyUVM RAL
                                                                   → regif_pkg.sv
                                                                   → regif_{name}_top.sv

For genrdl command:

Excel File → SystemRDL Generation → SystemRDL Compiler Validation → Final SystemRDL
                                                                   → regif_pkg.sv
                                                                   → regif_{name}_top.sv

The SystemRDL compiler validates:

• ✓ Register and field bit ranges
• ✓ Access permission combinations
• ✓ Address overlaps and conflicts
• ✓ Field property assignments
• ✓ Structural relationships
• ✓ SystemRDL syntax compliance

When the SystemRDL compiler finds issues:

• Compilation stops immediately
• Detailed error messages are provided to help fix your Excel file
• For pyral command:
  • With --keep-rdl, the intermediate SystemRDL file is preserved in the output directory for debugging
  • No PyUVM RAL model is generated until all validation errors are fixed
• For genrdl command:
  • The SystemRDL file is written to the output directory (e.g., mychip.rdl)
  • If validation fails, this file is preserved with the invalid content for debugging
  • You can fix the Excel file and run the command again to generate a correct SystemRDL file

To debug validation issues:

# Using pyral command with verbose output
pyral registers.xlsx --keep-rdl --verbose

# Using genrdl command with verbose output
genrdl registers.xlsx --verbose

# If compilation fails, examine the generated SystemRDL:
cat output/registers.rdl  # Look for where compilation stopped

3. Run Conversion

Using pyral (Generate PyUVM RAL)

# Generate PyUVM RAL model (all submodules)
pyral mychip.xlsx --keep-rdl

# Process only specific submodules
pyral mychip.xlsx -s GPIO UART --keep-rdl

# With custom top name and selective processing
pyral mychip.xlsx -s Memory_Controller -t mem_subsystem --output custom_output/

Using genrdl (Generate SystemRDL Only)

# Generate SystemRDL file (all submodules)
genrdl mychip.xlsx

# Process only specific submodules
genrdl mychip.xlsx -s GPIO UART

# With custom top name and selective processing
genrdl mychip.xlsx -s CPU_Core -t processor_top --verbose

4. Use Generated PyUVM RAL

# Import the generated RAL model
from output.mychip_ral import build_ral_model

# Build the RAL model in your test class
class MyTest(uvm_test):
    def __init__(self, name, parent):
        super().__init__(name, parent)
        self.ral = build_ral_model()
    
    async def run_phase(self, phase):
        # Access registers through proper hierarchy
        await self.ral.gpio0.CRTL_REG.write(0x5)
        data = await self.ral.uart0.RESET_REG.read()
        
        # Access individual fields
        await self.ral.gpio0.CRTL_REG.ENABLE.write(1)
        enable_val = await self.ral.gpio0.CRTL_REG.ENABLE.read()
        
        # Use with sequences
        reg_seq = uvm_reg_sequence.type_id.create("reg_seq")
        reg_seq.model = self.ral
        await reg_seq.start(None)

🎯 Advanced Features

Selective Submodule Processing

Process only specific submodules from your Excel file instead of all available sheets:

# Process only CPU and Memory submodules
pyral chip_design.xlsx -s CPU_Core Memory_Controller

# Generate SystemRDL for specific subsystem
genrdl full_chip.xlsx -s UART_Module SPI_Controller

# Combine with custom top name
pyral soc_design.xlsx -s ARM_Core L2_Cache -t processor_subsystem

Use Cases:

• Incremental Development: Test individual IP blocks during development
• Subsystem Testing: Generate RAL models for specific subsystems only
• Performance: Faster generation for large designs by processing subset
• CI/CD: Generate different RAL variants for different test scenarios

Smart Top-Level Naming

The tool automatically determines the top-level addrmap name using intelligent priority logic:

Priority Order:

1. Explicit Name (-t/--top-name): User-specified name takes highest priority
2. Selective Mode (-s/--submodules): Auto-generates {submodule_names}_top
3. Full Processing: Uses Excel filename (without extension)

Examples:

# Explicit naming (Priority 1)
pyral chip.xlsx -t MyCustomChip
# Result: MyCustomChip.rdl, MyCustomChip_ral.py

# Selective processing auto-naming (Priority 2)  
pyral chip.xlsx -s GPIO UART Timer
# Result: GPIO_UART_Timer_top.rdl, GPIO_UART_Timer_top_ral.py

# Default filename-based naming (Priority 3)
pyral my_processor.xlsx  
# Result: my_processor.rdl, my_processor_ral.py

Comprehensive Error Validation

The tool provides comprehensive validation with clear error messages:

Hierarchy Validation:

• Ensures all specified submodules exist in hierarchy sheet
• Validates consistency between register sheets and hierarchy definitions
• Provides clear error messages with available options

Excel Structure Validation:

• Verifies all specified sheets exist in Excel file
• Checks for required columns in register definitions
• Validates proper hierarchy sheet structure

SystemRDL Validation:

• Automatic compilation and validation of generated SystemRDL
• Catches register definition errors early
• Provides detailed error messages for quick debugging

Flexible Sheet Configuration

Customize sheet names to match your Excel file organization:

# Custom hierarchy sheet name
pyral design.xlsx --hierarchy-sheet "Module_Hierarchy"

# Custom default properties sheet
pyral design.xlsx --default-sheet "Global_Defaults"

# Both custom sheets with selective processing
pyral design.xlsx --hierarchy-sheet "Blocks" --default-sheet "Props" -s CPU GPU

🐍 Python API

ExcelToPyRALConverter Class

Main class that orchestrates the Excel → SystemRDL → PyUVM pipeline:

from excel2pyral import ExcelToPyRALConverter

# Initialize converter
converter = ExcelToPyRALConverter()

# Convert with all options
result = converter.convert(
    excel_file="registers.xlsx",      # Input Excel file
    output="output",                  # Output directory
    top_name="my_chip",               # Top-level module name (Priority 1)
    package_name="my_chip_ral",       # Generated package name
    hierarchy_sheet="Hierarchy",      # Name of submodule hierarchy sheet
    default_sheet="default",          # Name of default properties sheet
    submodule_sheets=["GPIO", "UART"], # Specific submodules to process (optional)
    keep_rdl=True,                    # Keep intermediate SystemRDL
)

# Returns a dictionary with file paths
print(f"Generated PyUVM RAL: {result['pyuvm_file']}")
print(f"Generated SystemRDL: {result['systemrdl_file']}")  # If keep_rdl=True

ExcelToSystemRDLImporter Class

For generating SystemRDL files only:

from excel2pyral import ExcelToSystemRDLImporter

# Initialize importer
importer = ExcelToSystemRDLImporter()

# Generate SystemRDL content
systemrdl_content = importer.excel_to_systemrdl(
    excel_file="mychip.xlsx",
    top_name="chip_top",               # Custom top name (optional)
    hierarchy_sheet="Hierarchy",       # Custom hierarchy sheet name (optional)
    default_sheet="default",           # Custom default sheet name (optional)
    submodule_sheets=["GPIO", "UART"]  # Process specific submodules (optional)
)

# Write to file
with open("output/chip.rdl", "w") as f:
    f.write(systemrdl_content)

Individual Components

# Use individual components
from excel2pyral import (
    ExcelToSystemRDLImporter,
    SystemRDLCompiler, 
    PyUVMRALGenerator,
    SVRegifGenerator,
)

# Step 1: Excel to SystemRDL
excel_importer = ExcelToSystemRDLImporter()
systemrdl_content = excel_importer.excel_to_systemrdl(
    excel_file="registers.xlsx",
    top_name="my_chip"
)

# Step 2: Compile SystemRDL
rdl_compiler = SystemRDLCompiler()
compiled_root = rdl_compiler.compile_string(systemrdl_content)

# Step 3: Generate PyUVM RAL
ral_generator = PyUVMRALGenerator()
ral_generator.generate(
    root_node=compiled_root,
    output_file="my_chip_ral.py"
)

SVRegifGenerator Class

Generates SystemVerilog register interface files directly from a .rdl file:

from excel2pyral import SVRegifGenerator

gen = SVRegifGenerator()
result = gen.generate(
    rdl_file="rdl_datacap.rdl",   # Input .rdl file
    output_dir="rtl/",            # Output directory
    pkg_name="regif_pkg",         # SV package name (optional, default: regif_pkg)
    struct_prefix="datacap",      # Struct prefix (optional — auto-detected)
    top_module_name=None,         # Module name (optional — defaults to regif_{prefix}_top)
    reg_data_width=None,          # Data width (optional — auto-detected from RDL regwidth)
)

print(result["pkg_file"])    # → rtl/regif_pkg.sv
print(result["top_file"])    # → rtl/regif_datacap_top.sv

What it generates:

Output file	Contents
regif_pkg.sv	SV package with {prefix}_reg_in_t and {prefix}_reg_out_t typedef structs
regif_{prefix}_top.sv	Glue module bridging peakrdl block to HW signal struct ports

Classification logic — fields classified by the hw access property:

RDL hw	Direction	Struct	Assignment
hw = w	HW writes (status)	{prefix}_reg_in_t	hwif_in.inst.REG.field.next = reg_in.REG[hi:lo]
hw = r	SW writes (control)	{prefix}_reg_out_t	reg_out.REG[hi:lo] = hwif_out.inst.REG.field.value

REG_DATA_WIDTH is auto-detected from default regwidth in the RDL — no manual parameter needed.

🏗️ Generated PyUVM Structure

The generated PyUVM RAL follows a clean Python-native structure with three layers:

Register Classes

Each register is a uvm_reg subclass. Fields are declared in __init__ and configured in build():

class CrtlReg(uvm_reg):
    """CRTL_REG"""

    def __init__(self, name="CRTL_REG", reg_width=32):
        super().__init__(name, reg_width)
        self.ENABLE = uvm_reg_field("ENABLE")
        self.MODE   = uvm_reg_field("MODE")

    def build(self):
        self.ENABLE.configure(self, size=1, lsb_pos=0, access="RW", is_volatile=False, reset=0x0)
        self.MODE.configure(  self, size=3, lsb_pos=1, access="RO", is_volatile=False, reset=0x0)
        self._set_lock()

is_volatile=True is set automatically when the hw access type in SystemRDL is w, rw, or rw1 — i.e. hardware can write the field (status/monitor registers).

Register Block Classes

Each regfile becomes a uvm_reg_block subclass. build() accepts a base_address parameter so the same class can be instantiated at different addresses:

class Gpio(uvm_reg_block):
    """GPIO — register block (default base 0x1000)."""

    def __init__(self, name="GPIO"):
        super().__init__(name)
        self.def_map = None

    def build(self, base_address=0x1000):
        self.def_map = uvm_reg_map("def_map")
        self.def_map.configure(self, base_address)
        self.default_map = self.def_map

        self.def_map.crtl_reg_reg = CrtlReg("crtl_reg_reg")
        self.def_map.crtl_reg_reg.configure(self, hex(base_address + 0x0), "", False, False)
        self.def_map.add_reg(self.def_map.crtl_reg_reg, "0", "RW")

        self.def_map.status_reg_reg = StatusReg("status_reg_reg")
        self.def_map.status_reg_reg.configure(self, hex(base_address + 0x4), "", False, False)
        self.def_map.add_reg(self.def_map.status_reg_reg, "0", "RW")

If the same regfile type is instantiated multiple times (e.g. gpio0, gpio1), only one class is generated and each instance is built with its own base_address.

Top-Level Container Class

The top addrmap becomes a plain Python class (not uvm_reg_block) that owns all block instances and wires them to the sequencer/adapter:

class MychipTop:
    """
    Top-level RAL container — holds one uvm_reg_block per hardware module.
    get_all_maps() and set_sequencer_adapter() discover sub-blocks automatically
    via Python introspection; no changes needed elsewhere when a new block is added.
    """

    def __init__(self, name="mychip_top"):
        self.name  = name
        self.gpio0 = Gpio("gpio0")
        self.gpio1 = Gpio("gpio1")
        self.uart0 = Uart("uart0")
        self.uart1 = Uart("uart1")

    def build(self):
        self.gpio0.build(base_address=0x1000)
        self.gpio1.build(base_address=0x1100)
        self.uart0.build(base_address=0x2000)
        self.uart1.build(base_address=0x3000)

    def get_all_maps(self):
        """Return default_map of every uvm_reg_block attribute."""
        return [
            getattr(self, attr).default_map
            for attr in vars(self)
            if isinstance(getattr(self, attr), uvm_reg_block)
        ]

    def set_sequencer_adapter(self, seqr, adp):
        """Wire adapter+sequencer on every sub-block map — call once from connect_phase."""
        for m in self.get_all_maps():
            m.set_sequencer(seqr)
            m.set_adapter(adp)

Best Practices

Excel File Organization

1. Use consistent naming: Keep module, register, and field names consistent
2. Group related functionality: Put similar registers together
3. Document thoroughly: Use description fields extensively
4. Validate addresses: Ensure no overlapping address ranges
5. Standard bit ranges: Use standard field sizes where possible

Module Design

1. Logical grouping: Group related registers in the same module
2. Address alignment: Align register addresses to natural boundaries
3. Reserved fields: Include reserved fields for future expansion

PyUVM Integration

1. Register model early: Create RAL model during build phase
2. Use callbacks: Implement register callbacks for monitoring
3. Enable coverage: Turn on register coverage for verification
4. Sequence integration: Use with standard UVM register sequences

Development Workflow

1. Start simple: Begin with basic register definitions
2. Test incrementally: Test after each module addition
3. Use version control: Track changes to Excel files
4. Keep intermediate files: Use --keep-rdl for debugging
5. Validate generated code: Review generated PyUVM RAL model

🐛 Troubleshooting

Common Issues

"Walker did not find any top-level addrmap block"

Cause: Missing or incorrectly formatted Hierarchy sheet Solution:

• Ensure Hierarchy sheet exists (or use --hierarchy-sheet for custom name)
• Check column names match exactly: "Submodule Name", "Instances", "Base Addresses"
• Verify sheet name matches the --hierarchy-sheet parameter (default: "Hierarchy")

"Requested submodules not found in hierarchy sheet"

Cause: Using -s/--submodules with submodule names that don't exist in the hierarchy sheet Solution:

• Check spelling of submodule names in the -s argument
• Verify the submodule names exist in the "Submodule Name" column of hierarchy sheet
• The error message shows available submodules for reference

"Found register sheets without corresponding entries in hierarchy sheet"

Cause: Excel contains register sheets that are not listed in the hierarchy (when not using -s) Solution:

• Add missing submodules to the hierarchy sheet, OR
• Use -s to process only specific submodules, OR
• Remove unused register sheets from the Excel file

"Specified submodule sheets not found in Excel file"

Cause: Using -s with sheet names that don't exist in the Excel file Solution:

• Check spelling of sheet names in the -s argument
• Verify the sheets exist in the Excel file
• Ensure sheet names match exactly (case-sensitive)

"SystemRDL compilation failed"

Cause: Invalid register/field definitions caught by SystemRDL compiler validation Solution: The SystemRDL compiler automatically validates your register descriptions and will catch issues such as:

• Invalid bit ranges: Ensures [MSB:LSB] format is correct and MSB >= LSB
• Unsupported access types: Validates that access types (RW, RO, WO, etc.) are legal
• Address conflicts: Detects overlapping register addresses
• Invalid field properties: Validates SystemRDL property assignments
• Structural issues: Checks for proper register and field relationships

To debug:

1. Use --keep-rdl --verbose to inspect the generated SystemRDL file
2. Review the SystemRDL compiler error messages for specific validation issues
3. Fix the corresponding entries in your Excel file

"No registers found in design"

Cause: Module type sheets missing or incorrectly named Solution:

• Ensure each Submodule Name in hierarchy sheet has corresponding sheet
• Check sheet names match Submodule Name exactly (case-sensitive)
• Verify register definitions have all required columns
• When using -s, ensure specified submodule sheets exist

Import errors in generated PyUVM

Cause: PyUVM not installed or wrong version Solution:

• Install PyUVM: pip install pyuvm
• Check Python environment is correct
• Verify all dependencies are installed

Debug Mode

Enable detailed debugging:

# For pyral command
pyral registers.xlsx --keep-rdl --verbose

# For genrdl command  
genrdl registers.xlsx --verbose

# With selective processing
pyral registers.xlsx -s GPIO UART --keep-rdl --verbose

This provides:

• Step-by-step conversion progress
• Intermediate SystemRDL file for inspection
• Detailed error messages with context
• Generated file locations and sizes

Validation Checklist

Before conversion, verify your Excel file:

• Hierarchy sheet exists with correct column names (or custom sheet name set with --hierarchy-sheet)
• All submodule types have corresponding sheets
• If using -s/--submodules, verify specified submodules exist in hierarchy sheet
• If using -s/--submodules, verify specified sheets exist in Excel file
• Register definitions have all required columns
• Bit ranges are in correct format [MSB:LSB]
• Access types are valid (RW, RO, WO, etc.)
• Addresses are in hexadecimal format
• No overlapping address ranges
• Field names are valid identifiers
• Reset values are properly formatted

Pre-Conversion Validation

Before running the conversion, manually verify your Excel file structure and content using the Validation Checklist above.

🤝 Contributing

Development Setup

git clone https://github.com/SanCodex/excel2pyral.git
cd excel2pyral

# Create virtual environment
python -m venv venv
source venv/bin/activate  # Linux/Mac
# venv\\Scripts\\activate  # Windows

# Install development dependencies
pip install -r requirements-dev.txt
pip install -e .

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• SystemRDL Compiler for SystemRDL support
• PyUVM for Python UVM framework
• PeakRDL ecosystem for inspiration

---

⭐ If this project helped you, please consider giving it a star on GitHub!