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
5.2.3.2.1. Instruction Cache
The instruction cache memory has the following characteristics:
- Direct-mapped cache implementation.
- 32 bytes (8 words) per cache line.
- The instruction master port reads an entire cache line at a time from memory, and issues one read per clock cycle.
- Critical word first.
- Virtually-indexed, physically-tagged, when MMU present.
The size of the tag field depends on the size of the cache memory and the physical address size. The size of the line field depends only on the size of the cache memory. The offset field is always five bits (i.e., a 32-byte line). The maximum instruction byte address size is 31 bits in systems without an MMU present. In systems with an MMU, the maximum instruction byte address size is 32 bits and the tag field always includes all the bits of the physical frame number (PFN).
The instruction cache is optional. However, excluding instruction cache from the Nios II/f core requires that the core include at least one tightly-coupled instruction memory.