Nios® V Processor Software Developer Handbook

ID 743810
Date 4/01/2024
Public
Document Table of Contents

8.7.1.1. Exception Cause Codes

Table 40.   Nios® V Processor Exception Cause Codes
Exception Cause Code Cause Symbol2
Instruction address misaligned 0 NIOSV_INSTRUCTION_ADDRESS_MISALIGNED
Instruction access fault 1 NIOSV_INSTRUCTION_ACCESS_FAULT
Illegal instruction 2 NIOSV_ILLEGAL_INSTRUCTION
Breakpoint 3 NIOSV_BREAKPOINT
Load address misaligned 4 NIOSV_LOAD_ADDRESS_MISALIGNED
Load access fault 5 NIOSV_LOAD_ACCESS_FAULT
Store/AMO address misaligned 6 NIOSV_STORE_AMO_ADDRESS_MISALIGNED
Store/AMO access fault 7 NIOSV_STORE_AMO_ACCESS_FAULT
Environment call from U-mode 8 NIOSV_ENVIRONMENT_CALL_FROM_U_MODE
Environment call from S-mode 9 NIOSV_ENVIRONMENT_CALL_FROM_S_MODE
Reserved 10 NIOSV_RESERVED_BIT_10
Environment call from M-mode 11 NIOSV_ENVIRONMENT_CALL_FROM_M_MODE
Instruction page fault 12 NIOSV_INSTRUCTION_PAGE_FAULT
Load page fault 13 NIOSV_LOAD_PAGE_FAULT
Reserved 14 NIOSV_RESERVED_BIT_14
Store/AMO page fault 15 NIOSV_STORE_AMO_PAGE_FAULT
Cause unknown3 -1 NIOSV_UNDEFINED_CAUSE
Note: It is possible for an instruction-related exception to occur during execution of an ISR.
2 Cause symbols are defined in sys/alt_exceptions.h.
3 This value is passed to the instruction-related exception handler if the cause argument if the cause is not known.