Catalog of SIP Cores
System on Chip design resources
System on Chip design resources
August 27, 2026 -
By Nick Flaherty, eeNews Europe
One of the key advantages and challenges of the RISC-V architecture is the ability to add custom instructions. Adding instructions to a RISC-V core can make a system more secure or boost performance in areas such as cryptography and edge AI. But these instructions also carry the risk of fragmentation, with different cores becoming incompatible.
There are three essential embedded extensions for the baseline RV32I and RV64I RISC-V cores that are commonly used. The C (Compressed Instructions) adds 16-bit variants of common 32-bit instructions and reduces code footprint by 15% to 30%, which is critical for constrained on-chip flash and ROM budgets. The E (Reduced Register Count) extension cuts the standard 32 integer registers down to 16 registers in RV32E, shrinking silicon area and lowering context-switching state overhead for tiny microcontrollers, while the M (Integer Multiplication and Division) extension provides hardware support for multiplying and dividing integers, replacing software routines with single-to-multi-cycle hardware execution.