VSRVES02 – Linux-capable RISC-V and VSDSP System-on-a-Chip

VSRVES02 is a low-power, Linux-capable, mixed-signal SoC that has two different cores suited for different tasks: a RISC-V core for running Linux-based protocols, and a VSDSP6 core for real-time signal processing tasks. VSRVES02 also contains a high-quality audio ADC and DAC, Ethernet, and other peripherals.

The VSRV2 RISC-V core, developed by VLSI Solution in Tristan project, is capable of running stock Linux. Linux boot time, including Ethernet networking, is only 1.4 seconds. As a speciality, Linux can be rebooted without interruption of audio playback.

Cores

• 32-bit Risc-V VSRV2 core capable of running Linux 6.6
• VSDSP⁶ signal processing core running VLSI's proprietary VSOS
• Both processor cores can run simultaneously in their own memories
• Both processors can access external LPDDR2 memory

RISC-V Running Linux

• RV32IMSUA Zicsr Zifencei Zba Zbb Zbs Zbkb Zicond core 
• Capable of running stock Linux 6.6 for RISC-V32
• MMU and 2x64 KiB I- and D-cache
• Boots Linux in less than 2 seconds
• Requires min 128 MiB 16-bit LPDDR2 to run Linux

VSDSP⁶ Running VSOS

• 512 KiB fast S-RAM for code and data
• VSOS multitasking Real-Time OS
• Boot time of about 1.5 seconds
• Loads 35 MiB Linux image from SD card in about 1.5 seconds
• Efficiently decodes HE-AAC, AC3, Aiff, Alac, Ape, DSD, Flac, MP3, Ogg Vorbis, RIFF WAV, and WMA files
• VSOS Shell Environment for easy prototyping and software development

Power

• (TBD)

Analog Audio

• 2 x 24-bit / DAC, 0-97.5 kHz, sample rate adjustable with 0.01 Hz steps
• 2 x 24-bit / ADC, 8, 16, 32, 48, 96, 192 kHz
• Stereo line output
• Stereo line input

Digital Audio

• Ethernet 10/100 MB/s RGMII interface
• SPDIF
• I2S
• I2S/TDM
• SPI
• USB
• UART

Memory

• SD card interface

General Purpose I/O of VSDSP⁶

• UARTs
• SPI
• GPIO
• SAR

General Purpose I/O of RISC-V

• UARTs
• SD card interface
• SPI
• GPIO

Other Hardware Features

• Operates with a single 12.288 MHz clock
• OTP
• optional RTC (with 32kHz XTAL)

Below is a list of various free and open resources available now or soon from VLSI Solution. They will be updated regulardly as new information becomes available. Our goal is to in time provide all information needed for our customers to compile and if necessary modify their own Linux kernels and applications.

Documentation:

• VSRVES01 and VSRVES02 Demonstrators (documentation related to the Tristan project)
• VSRV VSOS Shell - How to use the VSDSP VSOS Shell
• VSRV VSOS Audio - Introduction to the VSDSP VSOS audio subsystem

Software:

• Linux ethernet driver - Source code for the Ethernet driver required by VSRV1 (Note:. All other hardware features work without a custom driver)
• elf2vri - Linux C source code for program needed to convert Linux ELF and binary files to the VRI format required by CAT Board's DDRLoad