SlowerFire SoC

Aug 6, 2020
Perhaps you've heard of PolarFire Soc by Microchip.  It's a very capable Risc-V SoC with an FPGA component, but it will set you back nearly $500.

If you don't have that kind of cash and don't think you need the superior capabilities of that system, I present "SlowerFire SoC". The "SlowerFire Soc" is based on the DE0-Nano Altera Cyclone IV board that is loaded with the Linux-on-Litex-Vexriscv bits.

There are five components
Parts List:
DE0 Connections:
  • SPI Serial flash is SF_xxxx
  • I2C SEEPROM is at I2C_xxx
  • Serial is at SERIAL_xx
  • ENC28J60 is at E_xxxx
  • eclk25 is a 25MHz clock (for the ENC28J60 if it doesn't have an onboard clock)

GPIO_1FPGA PINDescription
_10F13SERIAL_RX
_11T15SERIAL_TX
_13T13SF CSN
_15T12SF MISO
_17T11SF MOSI
GND--GND
_19R11SF CLK
_111R10
_113P9
_115N11
_117K16E RST
_119L15I2C SCL
_121P16I2C SDA
_123N16E CSN(LED0)
GND--GND
_125P14E CLK
_127N14E MOSI
_129L13E MISO
_131K15E INT
_133J14eclk25

Follow the Linux-on-LiteX-Vexrsicv instruction to boot system

Login is root/root

Features & Specifications

  • PolarFire SoC (MPFS250T-FCVG484EES)SlowerFire
    • 600 50 MHz clock
    • 1 x RV64IMAC core by SiFive RV32I core by VexRiscv
    • 4 x RV64GC core by SiFive
    • 254K  22K (14.6K remaining) logic elements non-volatile fabric
    • 784 132x math block (18 x 18) (9x9)
    • 4 x 12.7 Gbps SERDES
    • Secure boot
  • Memory
    • 2 GB LPDDR4 x 32 32MB SDRAM x16
  • Storage
    • 1 Gb 16 MB SPI flash
    • 8 GB eMMC flash or SD card slot (multiplexed)
  • Networking
    • 2 x Gigabit  1x 10/100 Ethernet (runs about 350kb/s)
  • Expansion Interfaces
    • Raspberry Pi-compatible 40-pin header
    • mikroBUS socket
    • PCIe gen2
    • Micro USB 2.0 Hi-Speed OTG
    • 4 1 x UART (via TTL single micro USB)
    • 2 x CAN
    • SPI
    • I²C
  • Power
    • 12 5 VDC / 1A Mini-USB  5 A barrel jack input
    • On/off switch
    • I²C power monitor measuring four power rails
  • User Interfaces
    • 4 x User push button
    • 4 3 x User LED
    • 4 x Power status LED
  • Programming & Debugging
    • UART via micro USB
    • Onboard JTAG connector or embedded FlashPro6 (multiplexed)
    • 52 x test points