Tiny, Ultra-Low-Power Embedded RISC-V Processor

The BA5x-TN is a compact, ultra-low power, 32-bit, deeply embedded processor IP core.

With a two-stage execution pipeline, the processor implements the Embedded variant of the base RV32 ISA (RV32E). It uses just 16 general-purpose compressed instructions and omits other resource-demanding extensions. The core’s small silicon footprint, just 17k gates, is critical for minimizing leakage currents while idle and for reducing dynamic power consumption. Support for compressed instructions further enhances its power efficiency, as the resulting smaller firmware size not only lowers the energy consumed for instruction fetches to execute a specific task but also reduces the size of the non-volatile and/or volatile memories used to store the firmware. The power management interface also enables dynamic clock gating, unused module power shut-off, and dynamic frequency scaling of the bus and the CPU.

The compact BA5x-TN is exceptionally efficient and scores 3.0 Coremarks/MHz (more processing power per MHz than most processors in its class). This allows operating the core at low frequencies to further save power, or meeting more demanding embedded processing requirements, or any optimum combination of both.

Easy Integration and Low Risk

The processor core uses AMBA^® AXI4 or AHB-Lite, and low-latency Quick-access Memory (QMEM) interfaces for fetching instructions and accessing data and peripherals. The debug unit connects to an external JTAG/TAP controller via an APB port.

Part of the family of processor cores available from CAST for more than a decade and used by hundreds of customers, the BA5x-TN IP core has been designed for easy reuse and integration, has been rigorously verified, and is LINT-clean, scan-ready, and silicon-proven. It is available in Verilog source code.

To further accelerate development, the processor core can be delivered pre-integrated with bus infrastructure cores, typical microcontroller peripherals, memory controllers, and interconnect IP cores. Please contact CAST Sales for details.

Software Development

The BA5x-TN can be used with RISC-V compatible toolchains, libraries, and IDEs, or the included BeyondStudio™ IDE. This Eclipse-based Integrated Development Environment combines an instruction-level simulator and the latest version of the RISC-V GNU toolchain. Employed by numerous BAx processor users for over a decade, BeyondStudio is a complete and fully featured IDE.

Reference designs on FPGA development boards are available to ease evaluations and accelerate code development. Contact CAST Sales for more information.

Compact, Low-Power Architecture

• Small silicon footprint for lower leakage and dynamic CPU power
  • From 17k gates
• Advanced power management
  • Dynamic clock gating and unused units power shut off
  • Software- and hardware-controlled clock frequency scaling
• Single-issue, in-order, 2-stage pipeline
• Harvard architecture with separate instruction and data AXI-Lite and Quick-access Memory (QMEM) buses

Performance

• 3.0 Coremarks/MHz
• Over 500 MHz in 16 nm

RISC-V Features

• 32-bit Base RISC-V ISA (RV32E) with Compressed Instructions (C) enabled
• Core Local Interrupt Controller (CLINT) for timer and software interrupts
• Programmable Interrupt Controller (PIC) for up to 64 direct external interrupts
• Wait-for-Interrupt (WFI) puts the processor into a low-power state until an interrupt assertion

Available Pre-Integrated Platforms

• Bus fabric with peripherals such as GPIO, UART, Real-Time Clock, Timers, I2C, and SPI
• Optionally customized to include memory controllers, interconnects, and more from the CAST IP line

Low Risk & Flexible Licensing

• Industry-standard licensing terms with royalty-free options
• Reliable vendor with an extensive track record and excellent support
  • Thousands of IP core licenses, and billions of units shipped with IP from CAST since 1997
  • Experienced and responsive support team with a 24/7 culture

Debug and IDE Support

• JTAG Debug with hardware triggers
• Use standard RISC-V IDEs or the included Eclipse-based BeyondStudio™

• The core is available for ASICs in synthesizable Verilog.
• It includes everything required for successful implementation: extensive documentation, a testbench, a sample SoC design, and sample synthesis and simulation scripts.