README.AX25 1.2 KB
AX25 is Andes CPU IP to adopt RISC-V architecture.

Features
========

CPU Core
 - 5-stage in-order execution pipeline
 - Hardware Multiplier
	 - radix-2/radix-4/radix-16/radix-256/fast
 - Hardware Divider
 - Optional branch prediction
 - Machine mode and optional user mode
 - Optional performance monitoring

ISA
 - RV64I base integer instructions
 - RVC for 16-bit compressed instructions
 - RVM for multiplication and division instructions

Memory subsystem
 - I & D local memory
   - Size: 4KB to 16MB
 - Memory subsyetem soft-error protection
   - Protection scheme: parity-checking or error-checking-and-correction (ECC)
   - Automatic hardware error correction

Bus
 - Interface Protocol
   - Synchronous AHB (32-bit/64-bit data-width), or
   - Synchronous AXI4 (64-bit data-width)

Power management
 - Wait for interrupt (WFI) mode

Debug
 - Configurable number of breakpoints: 2/4/8
 - External Debug Module
   - AHB slave port
 - External JTAG debug transport module

Platform Level Interrupt Controller (PLIC)
 - AHB slave port
 - Configurable number of interrupts: 1-1023
 - Configurable number of interrupt priorities: 3/7/15/63/127/255
 - Configurable number of targets:  1-16
 - Preempted interrupt priority stack