NDS32¶
NDS32 is a new high-performance 32-bit RISC microprocessor core.
AndeStar ISA¶
AndeStar is a patent-pending 16-bit/32-bit mixed-length instruction set to achieve optimal system performance, code density, and power efficiency.
- It contains the following features:
Intermixable 32-bit and 16-bit instruction sets without the need for mode switch.
16-bit instructions as a frequently used subset of 32-bit instructions.
RISC-style register-based instruction set.
32 32-bit General Purpose Registers (GPR).
Upto 1024 User Special Registers (USR) for existing and extension instructions.
- Rich load/store instructions for…
Single memory access with base address update.
Multiple aligned and unaligned memory accesses for memory copy and stack operations.
Data prefetch to improve data cache performance.
Non-bus locking synchronization instructions.
PC relative jump and PC read instructions for efficient position independent code.
Multiply-add and multiple-sub with 64-bit accumulator.
Instruction for efficient power management.
Bi-endian support.
- Three instruction extension space for application acceleration:
Performance extension.
Andes future extensions (for floating-point, multimedia, etc.)
Customer extensions.
AndesCore CPU¶
Andes Technology has 4 families of CPU cores: N12, N10, N9, N8.
For details about N12 CPU family, please check below N1213 features. N1213 is a configurable hard/soft core of NDS32’s N12 CPU family.
N1213 Features¶
- CPU Core
16-/32-bit mixable instruction format.
32 general-purpose 32-bit registers.
8-stage pipeline.
Dynamic branch prediction.
32/64/128/256 BTB.
Return address stack (RAS).
Vector interrupts for internal/external. interrupt controller with 6 hardware interrupt signals.
3 HW-level nested interruptions.
User and super-user mode support.
Memory-mapped I/O.
Address space up to 4GB.
- Memory Management Unit
- TLB
4/8-entry fully associative iTLB/dTLB.
32/64/128-entry 4-way set-associati.ve main TLB.
TLB locking support
Optional hardware page table walker.
- Two groups of page size support.
4KB & 1MB.
8KB & 1MB.
- Memory Subsystem
- I & D cache.
Virtually indexed and physically tagged.
Cache size: 8KB/16KB/32KB/64KB.
Cache line size: 16B/32B.
Set associativity: 2-way, 4-way or direct-mapped.
Cache locking support.
- I & D local memory (LM).
Size: 4KB to 1MB.
Bank numbers: 1 or 2.
Optional 1D/2D DMA engine.
Internal or external to CPU core.
- Bus Interface
Synchronous/Asynchronous AHB bus: 0, 1 or 2 ports.
Synchronous High speed memory port. (HSMP): 0, 1 or 2 ports.
- Debug
JTAG debug interface.
Embedded debug module (EDM).
Optional embedded program tracer interface.
- Miscellaneous
Programmable data endian control.
Performance monitoring mechanism.
The NDS32 ports of u-boot, the Linux kernel, the GNU toolchain and other associated software are actively supported by Andes Technology Corporation.