32-bit Application Processor

Overview

The BA25 is a 32-bit processor for demanding systems running applications on general-purpose operating systems such as Linux and Android. The high-performance BA25 processor runs at high clock frequencies yet has a smaller silicon footprint than most competing application processors (e.g., over 1100MHz and from 145k sq. um in TSMC 28nm HPM, including the FPU, and excluding SRAMs).

This royalty-free 32-bit processor core is binary-compatible with other members of the silicon-proven BA2x processor family. Its BA2 instruction set is relatively simple and extremely compact, offering system area and energy savings benefits. Programing is facilitated with the included C/C++ tool chain, Eclipse IDE, architectural simulator, and ported C libraries, RTOSs, and OSs.

The seven-stage pipelined architecture runs at high frequencies and further enhances performance by supporting out-of-order execution and branch prediction. An optional IEEE 754 compliant floating-point unit accelerates floating point computations.

The BA25 processor uses two-level data and instruction caches—with L0 running at the CPU’s clock frequency and L1 running at half that—and a two-level memory management unit. The size and associativity of the caches and MMU are configurable at synthesis time. The system interface uses two AMBA® AXI4™ buses, one for data and one for instructions, both of configurable data width. Two tightly-coupled quick memory (QMEM) buses allow fast access for time-critical code and data, and can be used for inter-core communication in a multi-core architecture.

The energy efficiency BA25 enables power management with clock gating and power shut-off of unused units, and through software and hardware control over the clock frequency of the CPU and buses. Wake-up from sleep mode is triggered by an interrupt issued by the embedded tick-timer or by an external source.

Key Features

High Performance 32-bit CPU
Seven-Stage Pipeline
Out-of Order Completion
Sophisticated Branch Prediction
Optional Floating Point Unit
2.51 Coremarks/MHz
1100+ MHz on TSMC 28nm HPM
Efficient Power Management
Dynamic clock gating and power shut-off of unused units
Software- and hardware-controlled clock frequency
Wake-up on tick timer or external interrupt
Fast & Flexible Memory Access
Separate Instruction and Data Caches and MMU
AXI4 data & instruction buses (32-, 64- or 128-bit) with 4 GBytes direct addressable space on each bus
Tightly coupled Quick Memory (QMEM) interface for fast and deterministic access to code and/or data
Two-Level Cache and MMU
L0 cache running at core frequency and L1 cache running at half the core frequency
1–16 Kbytes L0 caches, up to four-way set associative
32–512 Kbytes L1 caches, up to four-way set associative
L0 MMU with up to 32 four-way associative entries
L1 MMU with up to 2048 four-way associative entries
Optional Integrated Peripherals
Vectored Interrupt Controller
Microcontroller peripherals such as GPIO, UART, Real-Time Clock, Timers, I2C, and SPI
Memory controllers, interconnect IP, and more
Easy Software Development
Non-intrusive JTAG debug/trace for both CPU and system
Complex chained watchpoint and breakpoint conditions
BeyondStudio™ complete IDE for Windows or Linux under Eclipse
Ported libraries and operating systems

Block Diagram

Applications

The royalty-free, high-performance BA25 processor core is suitable as the main system processor in a multitasking environment and is a competitive choice for designs running full operating systems such as Linux or Android.

Deliverables

The core is available for ASICs in synthesizable Verilog source code or for FPGAs in optimized netlists.
It includes everything required for successful implementation: extensive documentation, a testbench, a sample SoC design, sample synthesis and simulation scripts, and the BeyondStudio™ Eclipse-based software development IDE for Windows and Linux.
Reference designs on FPGA boards are also available; contact CAST Sales for information.

Technical Specifications

Maturity

Production Proven

Availability

Now

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