Overview

Riscduino is a Single 32 bit RISC V based SOC design pin compatible to arduino 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.
    * Dual 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 with 4 Chip select, supports both SPI flash and SRAM interface
    * 2 x UART with 16Byte FIFO
    * USB 1.1 Host
    * I2C Master
    * UART Master
    * Simple SPI Master with 4 Chip select
    * 6 Channel ADC (in Progress)
    * 6 x PWM
    * 3 x Timer (16 Bit), 1us/1ms/1second resolution
    * 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.

Riscduino derivatives

MPW Shuttle on Riscduino

MPW	Tape-out	Project Name	Project Details	Github	Efabless
MPW-2	18-June-2021	YiFive	Single 32bit RISCV core without cache + SDRAM Controller + WB Interconnect	Link	Link
MPW-3	15-Nov-2021	Riscduino	Single 32bit RISCV core without cache + Onchip SRAM + WB Interconnect	Link	Link
MPW-4	31-Dec-2021	Riscduino-R1	Single 32bit RISCV core with cache + Onchip SRAM + WB Inter Connect	Link	Link
MPW-5	21-Mar-2022	Riscduino-SCORE	Single 32bit RISCV core with cache + Onchip SRAM+ WB Cross Bar	Link	Link
MPW-5	21-Mar-2022	Riscduino-DCORE	Dual 32bit RISCV core with cache + Onchip SRAM+ WB Cross Bar	Link	Link
MPW-5	21-Mar-2022	Riscduino-QCORE	Quad 32bit RISCV core with cache + Onchip SRAM+ WB Cross Bar	Link	Link

SOC Pin Mapping

Carvel SOC provides 38 GPIO pins for user functionality. Riscduino SOC GPIO Pin Mapping as follows vs ATMEGA328 and Arudino

ATMGA328 Pin No	Functionality	Arudino Pin Name	Carvel Pin Mapping
Pin-1	PC6/RESET		digital_io[0]
Pin-2	PD0/RXD[0]	D0	digital_io[1]
Pin-3	PD1/TXD[0]	D1	digital_io[2]
Pin-4	PD2/RXD[1]/INT0	D2	digital_io[3]
Pin-5	PD3/INT1/OC2B(PWM0)	D3	digital_io[4]
Pin-6	PD4/TXD[1]	D4	digital_io[5]
Pin-7	VCC		-
Pin-8	GND		-
Pin-9	PB6/XTAL1/TOSC1		digital_io[6]
Pin-10	PB7/XTAL2/TOSC2		digital_io[7]
Pin-11	PD5/SS[3]/OC0B(PWM1)/T1	D5	digital_io[8]
Pin-12	PD6/SS[2]/OC0A(PWM2)/AIN0	D6	digital_io[9] /analog_io[2]
Pin-13	PD7/A1N1	D7	digital_io[10]/analog_io[3]
Pin-14	PB0/CLKO/ICP1	D8	digital_io[11]
Pin-15	PB1/SS[1]OC1A(PWM3)	D9	digital_io[12]
Pin-16	PB2/SS[0]/OC1B(PWM4)	D10	digital_io[13]
Pin-17	PB3/MOSI/OC2A(PWM5)	D11	digital_io[14]
Pin-18	PB4/MISO	D12	digital_io[15]
Pin-19	PB5/SCK	D13	digital_io[16]
Pin-20	AVCC		-
Pin-21	AREF		analog_io[10]
Pin-22	GND		-
Pin-23	PC0/ADC0	A0	digital_io[18]/analog_io[11]
Pin-24	PC1/ADC1	A1	digital_io[19]/analog_io[12]
Pin-25	PC2/ADC2	A2	digital_io[20]/analog_io[13]
Pin-26	PC3/ADC3	A3	digital_io[21]/analog_io[14]
Pin-27	PC4/ADC4/SDA	A4	digital_io[22]/analog_io[15]
Pin-28	PC5/ADC5/SCL	A5	digital_io[23]/analog_io[16]
Additional Pad used for Externam ROM/RAM/USB
Sflash	sflash_sck		digital_io[24]
SFlash	sflash_ss0		digital_io[25]
SFlash	sflash_ss1		digital_io[26]
SFlash	sflash_ss2		digital_io[27]
SFlash	sflash_ss3		digital_io[28]
SFlash	sflash_io0		digital_io[29]
SFlash	sflash_io1		digital_io[30]
SFlash	sflash_io2		digital_io[31]
SFlash	sflash_io3		digital_io[32]
SSRAM	dbg_clk_mon		digital_io[33]
SSRAM	uartm rxd		digital_io[34]
SSRAM	uartm txd		digital_io[35]
usb1.1	usb_dp		digital_io[36]
usb1.1	usb_dn		digital_io[37]