1 Introduction

The Data Visualizer Run Time (DVRT) middleware enables real-time variable streaming and monitoring between embedded applications and the Microchip MPLAB Data Visualizer. This CMSIS Pack provides a portable, standardized solution for bidirectional communication over USART, allowing developers to monitor and modify variables without halting the CPU.

By leveraging CMSIS-Driver APIs, the DVRT middleware ensures compatibility across ARM Cortex-M devices and simplifies integration with existing projects. The included ring buffer and interrupt-driven reception provide robust, low-latency communication for real-time debugging and visualization.

1.1 Included in this Release

This release provides comprehensive middleware support for real-time variable streaming. The following components are included:

DVRT Core Middleware
- Standardized APIs for variable streaming and monitoring
- Integrated ring buffer for robust RX handling (no user implementation required)
- DVRT_USART_RxHandler() callback for interrupt-driven reception
- DVRT_USART_StartReceive() API to start continuous reception
- Bidirectional communication for variable monitoring and control
CMSIS-Driver Integration
- USART communication via CMSIS-Driver (portable across Cortex-M devices)
- Compatible with any CMSIS-Driver USART implementation
Template Project
- configure_dvrt.c template for quick integration
Example Projects
- CNANO MCHP Driver DVRT Example

1.2 Installation Instructions

Dependencies:


#	Packs	Version
1	ARM::CMSIS	6.2.0 or later
2	ARM::CMSIS-Driver	Any compliant USART implementation

Installation steps:

VS Code: CMSIS Toolbox

Step 1: Install the DVRT Pack

Using the CMSIS-Toolbox CLI:
```
cpackget add Microchip::CMSIS-Driver_DVRT
```

Step 2: Add Required Packs and Components

Add the pack to your *.csolution.yml:

packs:
                    - pack: Microchip::CMSIS-Driver_DVRT

Add the component to your *.cproject.yml:

components:
                    - component: Middleware:DVRT:Core

Step 3: Configure Compiler Settings (GCC)

The Data Visualizer reads debug symbols from *.elf files. Add the following settings to your *.csolution.yml:

misc:
                    - for-compiler: GCC
                    C-CPP:
                    - -gdwarf-4
                    - -fms-extensions
                    - -Wno-unknown-attributes
                    ASM:
                    - -gdwarf-4

Ensure that debug symbols are enabled:

build-types:
                    - type: Debug
                    debug: on

Step 4: Add the Code Template

In VS Code, click the + icon next to Source Files and select "Add From Component Code Template", then choose "Middleware:DVRT:Core DVRT Example Template".
Verify installation:
```
cpackget list
```
Tip: Browse all available Microchip packs at packs.download.microchip.com

1.3 What is New?

This release introduces the DVRT middleware for ARM Cortex-M devices, focusing on an improved developer experience and seamless integration with MPLAB Data Visualizer:

Devices Supported
- Any ARM Cortex-M device with CMSIS-Core support
- Any device with a CMSIS-Driver USART implementation
- Tested on the PIC32CM-PL family (Cortex-M0+)
Introduction of DVRT Middleware
- Real-time variable streaming to the Microchip Data Visualizer
- Up to eight monitored variables simultaneously
- Configurable streaming interval (default 20 ms)
- Bidirectional communication for variable monitoring and control
- Integrated ring buffer (512 bytes by default) for robust RX handling
- Interrupt-driven reception via the DVRT_USART_RxHandler() callback
CMSIS-Driver Integration
- Portable USART communication via CMSIS-Driver APIs
- No vendor-specific dependencies in the middleware core
Developer Tools
- Template file (configure_dvrt.c) for quick integration
- Example project demonstrating usage with the PIC32CM-PL CNANO board
- Full API documentation accessible via the Software Components view

1.4 DVRT Limitations

This release offers robust middleware support for real-time variable streaming. However, the following limitations and restrictions currently apply:

Supported Development Environments
- Arm Keil Studio Pack (MDK v6)
  
  The DVRT middleware is fully supported in Visual Studio Code when using the Arm Keil Studio Pack (MDK v6) extensions.
  
  You can use either:
  - The ARM CMSIS Solution graphical user interface, or
  - The CMSIS-Toolbox command-line interface (CLI).
Compiler Requirements
- A GCC compiler is required, as it generates .elf files with proper debug symbols compatible with the MPLAB Data Visualizer.
- The DWARF-4 debug format is required (-gdwarf-4)
- Debug symbols must be enabled (debug: on)
Hardware Requirements
- An RX pin pull-up is required for reliable DVRT command reception
- The USART interrupt must be enabled for interrupt-driven reception
General Restrictions
- A maximum of eight variables can be monitored simultaneously (configurable via DYNAMIC_VAR_PTR_COUNT)
- Variables must be declared volatile and/or static and global to be visible to the Data Visualizer
- DVRT_Process() must be called consistently every ~1ms for reliable streaming

1.5 Revision History

Table 1-1. Revision History
Version	Date	Description
1.0.0	2026-05-28	Initial Release

Version 1.0.0 (2026-04-24)

New Features:

Initial release of the Data Visualizer Run Time (DVRT) middleware
Integrated ring buffer for robust RX handling
DVRT_USART_RxHandler() callback for interrupt-driven reception
DVRT_USART_StartReceive() API to start continuous reception
USART communication via CMSIS-Driver
SysTick-based periodic processing
Variable streaming to the Microchip Data Visualizer
Template file for quick integration

Known Issues:

None

Support

For support questions, contact Microchip Support through https://www.microchip.com/en-us/support.