3.4.2.1. The status Register
3.4.2.2. The estatus Register
3.4.2.3. The bstatus Register
3.4.2.4. The ienable Register
3.4.2.5. The ipending Register
3.4.2.6. The cpuid Register
3.4.2.7. The exception Register
3.4.2.8. The pteaddr Register
3.4.2.9. The tlbacc Register
3.4.2.10. The tlbmisc Register
3.4.2.11. The badaddr Register
3.4.2.12. The config Register
3.4.2.13. The mpubase Register
3.4.2.14. The mpuacc Register
3.7.1. Terminology
3.7.2. Exception Overview
3.7.3. Exception Latency
3.7.4. Reset Exceptions
3.7.5. Break Exceptions
3.7.6. Interrupt Exceptions
3.7.7. Instruction-Related Exceptions
3.7.8. Other Exceptions
3.7.9. Exception Processing Flow
3.7.10. Handling Nested Exceptions
3.7.11. Handling Nonmaskable Interrupts
3.7.12. Masking and Disabling Exceptions
3.7.7.1. Trap Instruction
3.7.7.2. Break Instruction
3.7.7.3. Unimplemented Instruction
3.7.7.4. Illegal Instruction
3.7.7.5. Supervisor-Only Instruction
3.7.7.6. Supervisor-Only Instruction Address
3.7.7.7. Supervisor-Only Data Address
3.7.7.8. Misaligned Data Address
3.7.7.9. Misaligned Destination Address
3.7.7.10. Division Error
3.7.7.11. Fast TLB Miss
3.7.7.12. Double TLB Miss
3.7.7.13. TLB Permission Violation
3.7.7.14. MPU Region Violation
3.9.1. Data Transfer Instructions
3.9.2. Arithmetic and Logical Instructions
3.9.3. Move Instructions
3.9.4. Comparison Instructions
3.9.5. Shift and Rotate Instructions
3.9.6. Program Control Instructions
3.9.7. Other Control Instructions
3.9.8. Custom Instructions
3.9.9. No-Operation Instruction
3.9.10. Potential Unimplemented Instructions
8.5.1. add
8.5.2. addi
8.5.3. and
8.5.4. andhi
8.5.5. andi
8.5.6. beq
8.5.7. bge
8.5.8. bgeu
8.5.9. bgt
8.5.10. bgtu
8.5.11. ble
8.5.12. bleu
8.5.13. blt
8.5.14. bltu
8.5.15. bne
8.5.16. br
8.5.17. break
8.5.18. bret
8.5.19. call
8.5.20. callr
8.5.21. cmpeq
8.5.22. cmpeqi
8.5.23. cmpge
8.5.24. cmpgei
8.5.25. cmpgeu
8.5.26. cmpgeui
8.5.27. cmpgt
8.5.28. cmpgti
8.5.29. cmpgtu
8.5.30. cmpgtui
8.5.31. cmple
8.5.32. cmplei
8.5.33. cmpleu
8.5.34. cmpleui
8.5.35. cmplt
8.5.36. cmplti
8.5.37. cmpltu
8.5.38. cmpltui
8.5.39. cmpne
8.5.40. cmpnei
8.5.41. custom
8.5.42. div
8.5.43. divu
8.5.44. eret
8.5.45. flushd
8.5.46. flushda
8.5.47. flushi
8.5.48. flushp
8.5.49. initd
8.5.50. initda
8.5.51. initi
8.5.52. jmp
8.5.53. jmpi
8.5.54. ldb / ldbio
8.5.55. ldbu / ldbuio
8.5.56. ldh / ldhio
8.5.57. ldhu / ldhuio
8.5.58. ldw / ldwio
8.5.59. mov
8.5.60. movhi
8.5.61. movi
8.5.62. movia
8.5.63. movui
8.5.64. mul
8.5.65. muli
8.5.66. mulxss
8.5.67. mulxsu
8.5.68. mulxuu
8.5.69. nextpc
8.5.70. nop
8.5.71. nor
8.5.72. or
8.5.73. orhi
8.5.74. ori
8.5.75. rdctl
8.5.76. rdprs
8.5.77. ret
8.5.78. rol
8.5.79. roli
8.5.80. ror
8.5.81. sll
8.5.82. slli
8.5.83. sra
8.5.84. srai
8.5.85. srl
8.5.86. srli
8.5.87. stb / stbio l
8.5.88. sth / sthio
8.5.89. stw / stwio
8.5.90. sub
8.5.91. subi
8.5.92. sync
8.5.93. trap
8.5.94. wrctl
8.5.95. wrprs
8.5.96. xor
8.5.97. xorhi
8.5.98. xori
3.6.1. Enabling ECC
The ECC is disabled on system reset. Before enabling the ECC, initialize the Nios® II RAM blocks to avoid spurious ECC errors.
The Nios® II processor executes the INITI instruction on each cache line, which initializes the instruction cache RAM. The RAM does not require special initialization because any detected ECC errors are ignored if the line is invalid; the line is invalid after INITI instructions initialize the tag RAM.
Nios® II processor instructions that write to every register (except register 0) initialize the register file RAM blocks. If shadow register sets are present, this step is performed for all registers in the shadow register set using the WRPRS instruction.
Nios® II processor instructions that write every TLB RAM location initialize the MMU TLB RAM. This RAM does not require special initialization.