Cobham Gaisler AB
LEON3/LEON3FT
LEON3 is a 32-bit processor core conforming to the IEEE-1754 (SPARC V8) architecture. It is designed for embedded applications, combining high performance with low complexity and low power consumption.
The LEON3 core has the following main features: 7-stage pipeline with Harvard architecture, separate instruction and data caches, memory management unit, hardware multiplier and divider, on-chip debug support and multi-processor extensions.
The LEON3 processor can be enhanced with fault-tolerance against SEU errors (referred to as LEON3FT). The fault-tolerance is focused on the protection of on-chip RAM blocks, which are used to implement IU/FPU register files and the cache memory. Configuring the processor to implement fault-tolerance enables additional internal registers, register fields and changes the processor’s plug&play device ID. This documentation describes both the LEON3 and LEON3FT versions of the processor.
The estimated resource utilization of the LEON3/LEON3FT is:
Estimations are for a general purpose system without FPU, but with DSU and MMU enabled.
The next figure shows the LEON3/LEON3FT interfaces.
The following is a summary of the features:
- SPARC V8 instruction set with V8e extensions
- Advanced 7-stage pipeline
- Hardware multiply, divide and MAC units
- Separate instruction and data cache (Harvard architecture) with snooping
- Configurable caches: 1 - 4 ways, 1 - 256 kbytes/way. Random, LRR or LRU replacement
- Local instruction and data scratch pad RAM, 1 - 512 Kbytes
- SPARC Reference MMU (SRMMU) with configurable TLB
- AMBA-2.0 AHB bus interface
- Advanced on-chip debug support with instruction and data trace buffer
- Symmetric Multi-processor support (SMP)
- Power-down mode and clock gating
- Robust and fully synchronous single-edge clock design
- Fault-tolerant and SEU-proof version available for space applications
- Register file SEU error-correction of up to 4 errors per 32-bit word
- Cache memory error-correction of up to 4 errors per tag or 32-bit word
- Autonomous and software transparent error handling
- No timing or performance impact due to error detection and correction
LEON3FT features: