7.4. Miscellaneous Operations
| Nios® II Processor | Nios® V Processor | ||
|---|---|---|---|
| Operation | Assembler Syntax | Operation | Assembler Syntax |
| Debugger Breakpoint |
break | Debugger Breakpoint | ebreak |
| Debugger Breakpoint Return |
bret | Debugger Breakpoint Return | dret |
| Custom Instruction | custom N, rC,rA, rB | Custom Instruction | Refer to custom_instruction_debug.xml to write the machine code. For example, “.4byte 0xe7978b”.
Note: If you use custom instructions to generate the BSP, you can find the .xml file in the BSP Project folder.
|
| status ← estatus PC ← ea |
eret | PC ← mepc | mret |
| rC ← PC + 4 | nextpc rC | xC ← PC + 4 PC ← PC + 4 |
jal xC, 4 |
| No Operation |
nop | No Operation | nop |
| Read from Control Register |
rdctl rC, ctlN | Read from Control Register | csrr xC, csr |
| Read from Previous Register Set |
rdprs rB, rA, IMM16 | Not available in Nios® V processor | - |
| Return from Subroutine |
ret | Return from Subroutine | ret |
| Trap | trap | Trap | ecall |
| Write to Control Register |
wrctl ctlN, rA | Write to Control Register | csrw csr, xC |
| Read to Previous Register Set |
wrprs rC, rA | Not Available in Nios® V processor | - |