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  1. 6c02c21 final gds oasis by Jeff DiCorpo · 1 year, 1 month ago main
  2. c69c77e uart master interface added by dineshannayya · 1 year, 1 month ago
  3. cb2d94c block diagram and doc update by dineshannayya · 1 year, 1 month ago
  4. aa9f18a MPW-4 submission with 8KB WishBone and 4KB TCM Memory by dineshannayya · 1 year, 1 month ago
  5. 24e8606 add new caravel by dineshannayya · 1 year, 1 month ago
  Riscduino 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 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.
    * industry-grade and silicon-proven Open-Source RISC-V core from syntacore 
    * 4KB SRAM for data memory
    * 8KB SRAM for program memory
    * Quad SPI Master
    * UART with 16Byte FIFO
    * USB 1.1 Host
    * I2C Master
    * Simple SPI Master
    * MBIST controller for 8KB Program memory
    * 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 Syntacore SCR1 Open-source RISV-V compatible MCU-class core. It is industry-grade and silicon-proven IP. Git link: https://github.com/syntacore/scr1

Block Diagram

RISC V Core Key feature

   * RV32I or RV32E ISA base + optional RVM and RVC standard extensions
   * Machine privilege mode only
   * 2 to 4 stage pipeline
   * Optional Integrated Programmable Interrupt Controller with 16 IRQ lines
   * Optional RISC-V Debug subsystem with JTAG interface
   * Optional on-chip Tightly-Coupled Memory

RISC V core customization Riscduino SOC

  • Update: Modified some of the system verilog syntax to basic verilog syntax to compile/synthesis in open source tool like simulator (iverilog) and synthesis (yosys).
  • Modification: Modified the AXI/AHB interface to wishbone interface towards instruction & data memory interface

SOC Memory Map

SOC Size

BlockTotal CellSeqCombo
RISC20982316417818
PINMUX569310224671
SPI712012815839
UART_I2C_USB_SPI1119624488748
WB_HOST27965882208
WB_INTC18781081770
SAR_ADC11818100
MBIST31255432582
TOTAL52908917243736

SOC Register Map

Register Map: Wishbone HOST
OffsetNameDescription
0x00GLBL_CTRL[RW] Global Wishbone Access Control Register
0x04BANK_CTRL[RW] Bank Selection, MSB 8 bit Address
0x08CLK_SKEW_CTRL1[RW] Clock Skew Control2
0x0cCLK_SKEW_CTRL2[RW] Clock Skew Control2
Register: GLBL_CTRL
BitsNameDescription
31:24ReseveredUnsused
23:20RTC_CLK_CTRLRTC Clock Div Selection
19:16CPU_CLK_CTRLCPU Clock Div Selection
15:12SDARM_CLK_CTRLSDRAM Clock Div Selection
10:8WB_CLK_CTRLCore Wishbone Clock Div Selection
7UART_I2C_SEL0 - UART , 1 - I2C Master IO Selection
5I2C_RSTI2C Reset Control
4UART_RSTUART Reset Control
3SDRAM_RSTSDRAM Reset Control
2SPI_RSTSPI Reset Control
1CPU_RSTCPU Reset Control
0WB_RSTWishbone Core Reset Control
Register: BANK_CTRL
BitsNameDescription
31:24ReseveredUnsused
7:0BANK_SELHolds the upper 8 bit address core Wishbone Address
Register: CLK_SKEW_CTRL1
BitsNameDescription
31:28ReseveredUnsused
27:24CLK_SKEW_WBWishBone Core Clk Skew Control
23:20CLK_SKEW_GLBLGlbal Register Clk Skew Control
19:16CLK_SKEW_SDRAMSDRAM Clk Skew Control
15:12CLK_SKEW_SPISPI Clk Skew Control
11:8CLK_SKEW_UARTUART/I2C Clk Skew Control
7:4CLK_SKEW_RISCRISC Clk Skew Control
3:0CLK_SKEW_WIWishbone Clk Skew Control
Register Map: SPI MASTER
OffsetNameDescription
0x00GLBL_CTRL[RW] Global SPI Access Control Register
0x04DMEM_CTRL1[RW] Direct SPI Memory Access Control Register1
0x08DMEM_CTRL2[RW] Direct SPI Memory Access Control Register2
0x0cIMEM_CTRL1[RW] Indirect SPI Memory Access Control Register1
0x10IMEM_CTRL2[RW] Indirect SPI Memory Access Control Register2
0x14IMEM_ADDR[RW] Indirect SPI Memory Address
0x18IMEM_WDATA[W] Indirect SPI Memory Write Data
0x1cIMEM_RDATA[R] Indirect SPI Memory Read Data
0x20SPI_STATUS[R] SPI Debug Status
Register: GLBL_CTRL
BitsNameDescription
31:16ReseveredUnsused
15:8SPI_CLK_DIVSPI Clock Div Rato Selection
7:4ReservedUnused
3:2CS_LATECS DE_ASSERTION CONTROL
1:0CS_EARLYCS ASSERTION CONTROL
Register: DMEM_CTRL1
BitsNameDescription
31:9ReseveredUnsused
8FSM_RSTDirect Mem State Machine Reset
7:6SPI_SWITCHPhase at which SPI Mode need to switch
5:4SPI_MODESPI Mode, 0 - Single, 1 - Dual, 2 - Quad, 3 - QDDR
3:0CS_SELECTCHIP SELECT
Register: DMEM_CTRL2
BitsNameDescription
31:24DATA_CNTTotal Data Byte Count
23:22DUMMY_CNTTotal Dummy Byte Count
21:20ADDR_CNTTotal Address Byte Count
19:16SPI_SEQSPI Access Sequence
15:8MODE_REGMode Register Value
7:0CMD_REGCommand Register Value
Register: IMEM_CTRL1
BitsNameDescription
31:9ReseveredUnsused
8FSM_RSTInDirect Mem State Machine Reset
7:6SPI_SWITCHPhase at which SPI Mode need to switch
5:4SPI_MODESPI Mode, 0 - Single, 1 - Dual, 2 - Quad, 3 - QDDR
3:0CS_SELECTCHIP SELECT
Register: IMEM_CTRL2
BitsNameDescription
31:24DATA_CNTTotal Data Byte Count
23:22DUMMY_CNTTotal Dummy Byte Count
21:20ADDR_CNTTotal Address Byte Count
19:16SPI_SEQSPI Access Sequence
15:8MODE_REGMode Register Value
7:0CMD_REGCommand Register Value
Register: IMEM_ADDR
BitsNameDescription
31:0ADDRIndirect Memory Address
Register: IMEM_WDATA
BitsNameDescription
31:0WDATAIndirect Memory Write Data
Register: IMEM_RDATA
BitsNameDescription
31:0RDATAIndirect Memory Read Data
Register: SPI_STATUS
BitsNameDescription
31:0DEBUGSPI Debug Status
Register Map: Global Register
OffsetNameDescription
0x00SOFT_REG0[RW] Software Register0
0x04RISC_FUSE[RW] Risc Fuse Value
0x08SOFT_REG2[RW] Software Register2
0x0cINTR_CTRL[RW] Interrupt Control
0x10SDRAM_CTRL1[RW] Indirect SPI Memory Access Control Register2
0x14SDRAM_CTRL2[RW] Indirect SPI Memory Address
0x18SOFT_REG6[RW] Software Register6
0x1CSOFT_REG7[RW] Software Register7
0x20SOFT_REG8[RW] Software Register8
0x24SOFT_REG9[RW] Software Register9
0x28SOFT_REG10[RW] Software Register10
0x2CSOFT_REG11[RW] Software Register11
0x30SOFT_REG12[RW] Software Register12
0x34SOFT_REG13[RW] Software Register13
0x38SOFT_REG14[RW] Software Register14
0x3CSOFT_REG15[RW] Software Register15
Register: RISC_FUSE
BitsNameDescription
31:0RISC_FUSERISC Core Fuse Value
Register: INTR_CTRL
BitsNameDescription
31:20ReservedUnused
19:17USER_IRQUser Interrupt generation toward riscv
16SOFT_IRQSoftware Interrupt generation toward riscv
15:0EXT_IRQExternal 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

Tool Sets

Riscduino Soc flow uses Openlane tool sets.

  1. Synthesis
    1. yosys - Performs RTL synthesis
    2. abc - Performs technology mapping
    3. OpenSTA - Pefroms static timing analysis on the resulting netlist to generate timing reports
  2. Floorplan and PDN
    1. init_fp - Defines the core area for the macro as well as the rows (used for placement) and the tracks (used for routing)
    2. ioplacer - Places the macro input and output ports
    3. pdn - Generates the power distribution network
    4. tapcell - Inserts welltap and decap cells in the floorplan
  3. Placement
    1. RePLace - Performs global placement
    2. Resizer - Performs optional optimizations on the design
    3. OpenPhySyn - Performs timing optimizations on the design
    4. OpenDP - Perfroms detailed placement to legalize the globally placed components
  4. CTS
    1. TritonCTS - Synthesizes the clock distribution network (the clock tree)
  5. Routing
    1. FastRoute - Performs global routing to generate a guide file for the detailed router
    2. CU-GR - Another option for performing global routing.
    3. TritonRoute - Performs detailed routing
    4. SPEF-Extractor - Performs SPEF extraction
  6. GDSII Generation
    1. Magic - Streams out the final GDSII layout file from the routed def
    2. Klayout - Streams out the final GDSII layout file from the routed def as a back-up
  7. Checks
    1. Magic - Performs DRC Checks & Antenna Checks
    2. Klayout - Performs DRC Checks
    3. Netgen - Performs LVS Checks
    4. CVC - Performs Circuit Validity Checks

Contacts

Report an issue: https://github.com/dineshannayya/riscduino/issues

Documentation