Riscduino Single Risc Core SOC
Permission to use, copy, modify, and/or distribute this soc for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOC IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOC INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOC.
Table of contents
Overview
Riscduino is a Single 32 bit RISC V based SOC design pin compatible to arudino platform and this soc targetted for efabless Shuttle program. This project uses only open source tool set for simulation,synthesis and backend tools. The SOC flow follow the openlane methodology and SOC environment is compatible with efabless/carvel methodology.
Riscduino Block Diagram
Key features
* Open sourced under Apache-2.0 License (see LICENSE file) - unrestricted commercial use allowed.
* Single 32 Bit RISC-V core
* 2KB SRAM for instruction cache
* 2KB SRAM for data cache
* 2KB SRAM for Tightly coupled memory - For Data Memory
* Quad SPI Master
* UART with 16Byte FIFO
* USB 1.1 Host
* I2C Master
* UART Master
* Simple SPI Master
* 6 Channel ADC (in Progress)
* 6 PWM
* Pin Compatbible to arudino uno
* Wishbone compatible design
* Written in System Verilog
* Open-source tool set
* simulation - iverilog
* synthesis - yosys
* backend/sta - openlane tool set
* Verification suite provided.
SOC Pin Mapping
Carvel SOC provides 38 GPIO pins for user functionality. Riscduino SOC GPIO Pin Mapping as follows vs ATMEGA328 and Arudino
RISC V Core
Riscduino SOC Integrated 32 Bits RISC V core. Initial version of Single core RISC-V core is picked from Syntacore SCR1 (https://github.com/syntacore/scr1)
RISC V core customization for Riscduino SOC
Following Design changes are done on the basic version of syntacore RISC core
* Some of the sv syntex are changed to standard verilog format to make compatibile with opensource tool iverilog & yosys
* Instruction Request are changed from Single word to 4 Word Burst
* Multiplication and Divsion are changed to improve timing
* Additional pipe line stages added to improve the RISC timing closure near to 50Mhz
* 2KB instruction cache
* 2KB data cache
* Additional router are added towards instruction cache
* Additional router are added towards data cache
* Modified AXI/AHB interface to wishbone interface for instruction and data memory interface
Block Diagram
RISC V Core Key feature
* RV32I or RV32E ISA base + optional RVM and RVC standard extensions
* Machine privilege mode only
* 2 to 5 stage pipeline
* 2KB icache
* 2KB dcache
* Optional Integrated Programmable Interrupt Controller with 16 IRQ lines
* Optional RISC-V Debug subsystem with JTAG interface
* Optional on-chip Tightly-Coupled Memory
6 Channel SAR ADC
In Process - Looking for community help ...
SOC Memory Map
SOC Size
| Block | Total Cell | Seq | Combo |
|---|
| RISC | 20982 | 3164 | 17818 |
| PINMUX | 5693 | 1022 | 4671 |
| SPI | 7120 | 1281 | 5839 |
| UART_I2C_USB_SPI | 11196 | 2448 | 8748 |
| WB_HOST | 2796 | 588 | 2208 |
| WB_INTC | 1878 | 108 | 1770 |
| SAR_ADC | 118 | 18 | 100 |
| MBIST | 3125 | 543 | 2582 |
| | | |
| TOTAL | 52908 | 9172 | 43736 |
SOC Register Map
Register Map: Wishbone HOST
| Offset | Name | Description |
|---|
| 0x00 | GLBL_CTRL | [RW] Global Wishbone Access Control Register |
| 0x04 | BANK_CTRL | [RW] Bank Selection, MSB 8 bit Address |
| 0x08 | CLK_SKEW_CTRL1 | [RW] Clock Skew Control2 |
| 0x0c | CLK_SKEW_CTRL2 | [RW] Clock Skew Control2 |
Register: GLBL_CTRL
| Bits | Name | Description |
|---|
| 31:24 | Resevered | Unsused |
| 23:20 | RTC_CLK_CTRL | RTC Clock Div Selection |
| 19:16 | CPU_CLK_CTRL | CPU Clock Div Selection |
| 15:12 | SDARM_CLK_CTRL | SDRAM Clock Div Selection |
| 10:8 | WB_CLK_CTRL | Core Wishbone Clock Div Selection |
| 7 | UART_I2C_SEL | 0 - UART , 1 - I2C Master IO Selection |
| 5 | I2C_RST | I2C Reset Control |
| 4 | UART_RST | UART Reset Control |
| 3 | SDRAM_RST | SDRAM Reset Control |
| 2 | SPI_RST | SPI Reset Control |
| 1 | CPU_RST | CPU Reset Control |
| 0 | WB_RST | Wishbone Core Reset Control |
Register: BANK_CTRL
| Bits | Name | Description |
|---|
| 31:24 | Resevered | Unsused |
| 7:0 | BANK_SEL | Holds the upper 8 bit address core Wishbone Address |
Register: CLK_SKEW_CTRL1
| Bits | Name | Description |
|---|
| 31:28 | Resevered | Unsused |
| 27:24 | CLK_SKEW_WB | WishBone Core Clk Skew Control |
| 23:20 | CLK_SKEW_GLBL | Glbal Register Clk Skew Control |
| 19:16 | CLK_SKEW_SDRAM | SDRAM Clk Skew Control |
| 15:12 | CLK_SKEW_SPI | SPI Clk Skew Control |
| 11:8 | CLK_SKEW_UART | UART/I2C Clk Skew Control |
| 7:4 | CLK_SKEW_RISC | RISC Clk Skew Control |
| 3:0 | CLK_SKEW_WI | Wishbone Clk Skew Control |
Register Map: SPI MASTER
| Offset | Name | Description |
|---|
| 0x00 | GLBL_CTRL | [RW] Global SPI Access Control Register |
| 0x04 | DMEM_CTRL1 | [RW] Direct SPI Memory Access Control Register1 |
| 0x08 | DMEM_CTRL2 | [RW] Direct SPI Memory Access Control Register2 |
| 0x0c | IMEM_CTRL1 | [RW] Indirect SPI Memory Access Control Register1 |
| 0x10 | IMEM_CTRL2 | [RW] Indirect SPI Memory Access Control Register2 |
| 0x14 | IMEM_ADDR | [RW] Indirect SPI Memory Address |
| 0x18 | IMEM_WDATA | [W] Indirect SPI Memory Write Data |
| 0x1c | IMEM_RDATA | [R] Indirect SPI Memory Read Data |
| 0x20 | SPI_STATUS | [R] SPI Debug Status |
Register: GLBL_CTRL
| Bits | Name | Description |
|---|
| 31:16 | Resevered | Unsused |
| 15:8 | SPI_CLK_DIV | SPI Clock Div Rato Selection |
| 7:4 | Reserved | Unused |
| 3:2 | CS_LATE | CS DE_ASSERTION CONTROL |
| 1:0 | CS_EARLY | CS ASSERTION CONTROL |
Register: DMEM_CTRL1
| Bits | Name | Description |
|---|
| 31:9 | Resevered | Unsused |
| 8 | FSM_RST | Direct Mem State Machine Reset |
| 7:6 | SPI_SWITCH | Phase at which SPI Mode need to switch |
| 5:4 | SPI_MODE | SPI Mode, 0 - Single, 1 - Dual, 2 - Quad, 3 - QDDR |
| 3:0 | CS_SELECT | CHIP SELECT |
Register: DMEM_CTRL2
| Bits | Name | Description |
|---|
| 31:24 | DATA_CNT | Total Data Byte Count |
| 23:22 | DUMMY_CNT | Total Dummy Byte Count |
| 21:20 | ADDR_CNT | Total Address Byte Count |
| 19:16 | SPI_SEQ | SPI Access Sequence |
| 15:8 | MODE_REG | Mode Register Value |
| 7:0 | CMD_REG | Command Register Value |
Register: IMEM_CTRL1
| Bits | Name | Description |
|---|
| 31:9 | Resevered | Unsused |
| 8 | FSM_RST | InDirect Mem State Machine Reset |
| 7:6 | SPI_SWITCH | Phase at which SPI Mode need to switch |
| 5:4 | SPI_MODE | SPI Mode, 0 - Single, 1 - Dual, 2 - Quad, 3 - QDDR |
| 3:0 | CS_SELECT | CHIP SELECT |
Register: IMEM_CTRL2
| Bits | Name | Description |
|---|
| 31:24 | DATA_CNT | Total Data Byte Count |
| 23:22 | DUMMY_CNT | Total Dummy Byte Count |
| 21:20 | ADDR_CNT | Total Address Byte Count |
| 19:16 | SPI_SEQ | SPI Access Sequence |
| 15:8 | MODE_REG | Mode Register Value |
| 7:0 | CMD_REG | Command Register Value |
Register: IMEM_ADDR
| Bits | Name | Description |
|---|
| 31:0 | ADDR | Indirect Memory Address |
Register: IMEM_WDATA
| Bits | Name | Description |
|---|
| 31:0 | WDATA | Indirect Memory Write Data |
Register: IMEM_RDATA
| Bits | Name | Description |
|---|
| 31:0 | RDATA | Indirect Memory Read Data |
Register: SPI_STATUS
| Bits | Name | Description |
|---|
| 31:0 | DEBUG | SPI Debug Status |
Register Map: Global Register
| Offset | Name | Description |
|---|
| 0x00 | SOFT_REG0 | [RW] Software Register0 |
| 0x04 | RISC_FUSE | [RW] Risc Fuse Value |
| 0x08 | SOFT_REG2 | [RW] Software Register2 |
| 0x0c | INTR_CTRL | [RW] Interrupt Control |
| 0x10 | SDRAM_CTRL1 | [RW] Indirect SPI Memory Access Control Register2 |
| 0x14 | SDRAM_CTRL2 | [RW] Indirect SPI Memory Address |
| 0x18 | SOFT_REG6 | [RW] Software Register6 |
| 0x1C | SOFT_REG7 | [RW] Software Register7 |
| 0x20 | SOFT_REG8 | [RW] Software Register8 |
| 0x24 | SOFT_REG9 | [RW] Software Register9 |
| 0x28 | SOFT_REG10 | [RW] Software Register10 |
| 0x2C | SOFT_REG11 | [RW] Software Register11 |
| 0x30 | SOFT_REG12 | [RW] Software Register12 |
| 0x34 | SOFT_REG13 | [RW] Software Register13 |
| 0x38 | SOFT_REG14 | [RW] Software Register14 |
| 0x3C | SOFT_REG15 | [RW] Software Register15 |
Register: RISC_FUSE
| Bits | Name | Description |
|---|
| 31:0 | RISC_FUSE | RISC Core Fuse Value |
Register: INTR_CTRL
| Bits | Name | Description |
|---|
| 31:20 | Reserved | Unused |
| 19:17 | USER_IRQ | User Interrupt generation toward riscv |
| 16 | SOFT_IRQ | Software Interrupt generation toward riscv |
| 15:0 | EXT_IRQ | External Interrupt generation toward riscv |
Repository contents
|verilog
| ├─ rtl
| | |- syntacore
| | | |─ scr1
| | | | ├─ **docs** | **SCR1 documentation**
| | | | | ├─ scr1_eas.pdf | SCR1 External Architecture Specification
| | | | | └─ scr1_um.pdf | SCR1 User Manual
| | | | |─ **src** | **SCR1 RTL source and testbench files**
| | | | | ├─ includes | Header files
| | | | | ├─ core | Core top source files
| | | | | ├─ top | Cluster source files
| | | | |─ **synth** | **SCR1 RTL Synthesis files **
| | |- Qspi_master
| | | |- src | Qard SPI Master Source files
| | |-wb_interconnect
| | | |- src | 3x4 Wishbone Interconnect
| | |- digital_core
| | | |- src | Digital core Source files
| | |- lib | common library source files
| |- dv
| | |- la_test1 | carevel LA test
| | |- risc_boot | user core risc boot test
| | |- wb_port | user wishbone test
| | |- user_risc_boot | user standalone test without carevel soc
| |- gl | ** GLS Source files **
|
|- openlane
|- spi_master | spi_master openlane scripts
|- syntacore | Risc Core openlane scripts
|- user_project_wrapper | carvel user project wrapper
Prerequisites
- Docker (ensure docker daemon is running) -- tested with version 19.03.12, but any recent version should suffice.
Step-1: Docker in ubuntu 20.04 version
sudo apt update
sudo apt-get install apt-transport-https curl rtificates -agent software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable"
sudo apt update
apt-cache policy docker-ce
sudo apt install docker-ce
#Add User Name to docker
sudo usermod -aG docker <your user name>
# Reboot the system to enable the docker setup
Step-2: Update the Submodule, To to project area
git submodule init
git submodule update
Step-3: clone Openlane scripts under workarea
git clone https://github.com/The-OpenROAD-Project/OpenLane.git
Step-4: add Environment setting
export CARAVEL_ROOT=<Carvel Installed Path>
export OPENLANE_ROOT=<OpenLane Installed Path>
export OPENLANE_IMAGE_NAME=efabless/openlane:latest
export PDK_ROOT=<PDK Installed PATH>
export PDK_PATH=<PDK Install Path>/sky130A
Step-5: To install the PDK
source ~/.bashrc
cd OpenLane
make pdk
Tests preparation
The simulation package includes the following tests:
- risc_boot - Simple User Risc core boot
- wb_port - User Wishbone validation
- user_risc_boot - Standalone User Risc core boot
- user_mbist_test1 - Standalone MBIST test
- user_spi - Standalone SPI test
- user_i2c - Standalone I2C test
- user_risc_soft_boot - Standalone Risc with SRAM as Boot
Running Simulation
Examples:
make verify-wb_port
make verify-risc_boot
make verify-user_uart
make verify-user_spi
make verify-user_i2cm
make verify-user_risc_boot
make verify-wb_port SIM=RTL DUMP=OFF
make verify-wb_port SIM=RTL DUMP=ON
make verify-riscv_regress
Tool Sets
Riscduino Soc flow uses Openlane tool sets.
- Synthesis
yosys - Performs RTL synthesisabc - Performs technology mappingOpenSTA - Pefroms static timing analysis on the resulting netlist to generate timing reports
- Floorplan and PDN
init_fp - Defines the core area for the macro as well as the rows (used for placement) and the tracks (used for routing)ioplacer - Places the macro input and output portspdn - Generates the power distribution networktapcell - Inserts welltap and decap cells in the floorplan
- Placement
RePLace - Performs global placementResizer - Performs optional optimizations on the designOpenPhySyn - Performs timing optimizations on the designOpenDP - Perfroms detailed placement to legalize the globally placed components
- CTS
TritonCTS - Synthesizes the clock distribution network (the clock tree)
- Routing
FastRoute - Performs global routing to generate a guide file for the detailed routerCU-GR - Another option for performing global routing.TritonRoute - Performs detailed routingSPEF-Extractor - Performs SPEF extraction
- GDSII Generation
Magic - Streams out the final GDSII layout file from the routed defKlayout - Streams out the final GDSII layout file from the routed def as a back-up
- Checks
Magic - Performs DRC Checks & Antenna ChecksKlayout - Performs DRC ChecksNetgen - Performs LVS ChecksCVC - Performs Circuit Validity Checks
News
MPW Shuttle
Contacts
Report an issue: https://github.com/dineshannayya/riscduino/issues
Documentation
News on Riscduino
