Shakti_riscv_hal

This crate is hardware abstraction layer for Shakti's C-class PARASU,PINAKA and E-class VAJRA processor which is riscv architecture.

SHAKTI is an open-source initiative by the Reconfigurable Intelligent Systems Engineering (RISE) group at IIT-Madras . The aim of the SHAKTI initiative includes building open source production grade processors, complete System on Chips (SoCs), development boards and SHAKTI-based software platform. The SHAKTI project is building a family of 6 processors, based on the RISC-V ISA. There is a road-map to develop reference System on Chips (SoC) for each class of processors, which will serve as an exemplar for that family . The team has channelized years of research on processor architecture to build these SoCs which has competitive commercial offerings in the market with respect to occupied power, area and performance. The current SoC (as of December 2019) developments are for the Controller (C- Class) and Embedded (E- Class) classes .

Processors SHAKTI is a RISC-V based processor developed at RISE lab, IIT Madras. SHAKTI has envisioned a family of processors as part of its road-map, catering to different segments of the market. They have been broadly categorized into "Base Processors", "Multi-Core Processors" and "Experimental Processors" . The E and C-classes are the first set of indigenous processors aimed at Internet of Things (IoT), Embedded and Desktop markets. The processor design is free of any royalty and is open-sourced under BSD3 license. A brief overview of the E and C-classes of processors is described below.

E-class The E-Class is a 32 bit micro processor capable of supporting all extensions of RISC-V ISA as listed in Table 1. The E-class is an In-order 3-stage pipeline having an operational frequency of less than 200MHz on silicon. It is positioned against ARM’s M-class (CorTexM series) cores . The major anticipated use of the E-class of processors is in lowpower compute environments, automotive and IoT applications such as smart-cards, motor-controls and home automation. The E-class is also capable of running Real Time Operating Systems (RTOS) like Zephyr OS and FreeRTOS.

PINAKA (E32-A35) is a SoC built around E-class. Pinaka is a 32-bit E-class micro controller with 4KB ROM and 128KB BRAM, has 32 General Purpose Input Output (GPIO) pins (out of which upper 8 GPIO pins are dedicated to onboard LEDs and switches), a Platform Level Interrupt Controller (PLIC), a Timer (CLINT), 2 Serial Peripheral (SPI), 3 Universal Asynchronous Receiver Transmitter (UART), 2 Inter Integrated Circuit (I2C), 6 Pulse Width Modulator (PWM), an in-built Xilinx Analog Digital Converter (X-ADC), Soft Float library support, Physical Memory Protection (PMP) enabled, onboard FTDI based debugger and Pin Mux support (Arduino compatible pin assignments). Table 2 describes in detail.

PARASHU (E32-A100) is a SoC built around E-class. Parashu is a 32-bit E-class micro controller with 4 KB of ROM and 256 MB of DDR. The rest of the configuration in this SoC, is the same as PINAKA.

C-class The C-class is an in-order 6-stage 64-bit micro controller supporting the entire RISCV ISA. It targets the mid-range compute systems supporting 200-800MHz. C-class targets compute applications in the 0.5-1.5 Ghz range. The C-class is customizable for lowpower and high-performance variants. It is positioned against ARM’s Cortex A35/A55. Linux, SEL4 and FreeRTOS are some of the Operating Systems ported and verified with C-class.

VAJRA(C64-A100) is an SoC built around C-class. This SoC is a single-chip 64-bit C-class micro controller with 4KB of ROM and 256MB DDR3 RAM. VAJRA is aimed at mid-range application workloads like Industrial controllers and Desktop market.