PULPino is an open-source single-core microcontroller system, based on 32-bit RISC-V cores developed at ETH Zurich. PULPino is configurable to use either the RISCY or the zero-riscy core.

 

RISCY is an in-order, single-issue core with 4 pipeline stages and it has an IPC close to 1, full support for the base integer instruction set (RV32I), compressed instructions (RV32C) and multiplication instruction set extension (RV32M). It can be configured to have single-precision floating-point instruction set extension (RV32F). It implements several ISA extensions such as: hardware loops, post-incrementing load and store instructions, bit-manipulation instructions, MAC operations, support fixed-point operations, packed-SIMD instructions and the dot product. It has been designed to increase the energy efficiency of in ultra-low-power signal processing applications. RISCY implementes a subset of the 1.9 privileged specification.

 

zero-riscy is an in-order, single-issue core with 2 pipeline stages and it has full support for the base integer instruction set (RV32I) and compressed instructions (RV32C). It can be configured to have multiplication instruction set extension (RV32M) and the reduced number of registers extension (RV32E). It has been designed to target ultra-low-power and ultra-low-area constraints. zero-riscy implementes a subset of the 1.9 privileged specification.

 

When the core is idle, the platform can be put into a low power mode, where only a simple event unit is active and everything else is clock-gated and consumes minimal power (leakage). A specialized event unit wakes up the core in case an event/interrupt arrives.

 

For communication with the outside world, PULPino contains a broad set of peripherals, including I2S, I2C, SPI and UART. The platform internal devices can be accessed from outside via JTAG and SPI which allows pre-loading RAMs with executable code. In standalone mode, the platform boots from an internal boot ROM and loads its program from an external SPI flash.

 

The PULPino platform is available for RTL simulation as well FPGA. PULPino has been taped-out as an ASIC in UMC 65nm in January 2016. It has full debug support on all targets. In addition we support extended profiling with source code annotated execution times through KCacheGrind in RTL simulations.

 

You can download PULPino here