IBM A2
The IBM A2 is an open source massively multicore capable and multithreaded 64-bit Power ISA processor core designed by IBM using the Power ISA v.2.06 specification. Versions of processors based on the A2 core range from a 2.3 GHz version with 16 cores consuming 65 W to a less powerful, four core version, consuming 20 W at 1.4 GHz. Design The A2 core is a processor core designed for customization and embedded use in system on chip-devices, and was developed following IBM's game console processor designs, the Xbox 360-processor and Cell processor for the PlayStation 3. A2I A2I is a 4-way simultaneous multithreaded core which implements the 64-bit Power ISA v.2.06 Book III-E embedded platform specification with support for the embedded hypervisor features. It was designed for implementations with many cores and focusing on high throughput and many simultaneous threads. A2I was written in VHDL. The core has 4×32 64-bit general purpose registers (GPR) with full support for both little and big endian byte ordering, 16 KB+16 KB instruction and data cache and is capable of four-way multithreading. It has a fine grain branch prediction unit (BPU) with eight 1024-entry branch history tables. The L1 caches is a 16 KB