The Berkeley Out-of-Order Machine (BOOM)

Detailed BOOM Pipeline

Fig. 1 Detailed BOOM Pipeline. *’s denote where the core can be configured.

The Berkeley Out-of-Order Machine (BOOM) is heavily inspired by the MIPS R10000 [1] and the Alpha 21264 [2] out–of–order processors. Like the MIPS R10000 and the Alpha 21264, BOOM is a unified physical register file design (also known as “explicit register renaming”).

BOOM implements the open-source RISC-V ISA and utilizes the Chisel hardware construction language to construct generator for the core. A generator can be thought of a generialized RTL design. A standard RTL design can be viewed as a single instance of a generator design. Thus, BOOM is a family of out-of-order designs rather than a single instance of a core. Additionally, to build an SoC with a BOOM core, BOOM utilizes the Rocket Chip SoC generator as a library to reuse different micro-architecture structures (TLBs, PTWs, etc).

[1]Yeager, Kenneth C. “The MIPS R10000 superscalar microprocessor.” IEEE micro 16.2 (1996): 28-41.
[2]Kessler, Richard E. “The alpha 21264 microprocessor.” IEEE micro 19.2 (1999): 24-36.