NICE: Domain Specific Extension Solution  
NICE (Nuclei Instruction Co-Unit Extension) allows customers to add user-defined instructions to customize their  
processor implementation, also including the extension of tightly coupled register and memory access  
instructions.  
Define user-define  
instructions  
Domain Specific  
Domain Specific  
Domain Specific  
1
.
2. Accelerator  
3. Lib/Function  
4. Applications  
Custom Processor  
RISC-V ISA  
Custom SDK  
Applications/Algorithms  
Domain-Specific Libraries  
Intrinsic Function  
Domain-Specific  
Libraries  
Extension Unit  
Standard  
NICE IF  
Intrinsic  
Functions  
Extensions  
Core  
Custom Processor  
Identify user-defined instructions  
by program profiling  
Implement the application-  
specific co-unit following the  
NICE interface  
No requirement for tool-chain update  
Using Intrinsic Function or  
encapsulated libraries  
Standard ISA + Extensions  
Extension  
instructions  
Extension  
Define extension instructions into  
RISC-V reserved ISA space  
Unit  
I
F
I
RISC-V standard  
D
instructions  
W
B
uCore