saltzmanj
commented
7 years ago Reliability Instructions
Description
| Instruction | Description |
|---|---|
| Check Instruction | Activates the instruction checker module for the immediately following instruction by comparing a redundant version of the instruction elsewhere in memory. The address of the redundant instruction is [R15 + <9 bit immediate offset> ]. |
Encoding
| Instruction | 15:13 | 12 | 11:9 | 8:0 |
|---|---|---|---|---|
| Check Instruction | 000 | 1 | 000 | Offset into redundancy table |
Assembly
Check Instruction
-- Load address of redundancy table
LIL R15, 0x00
LIH R15, 0x80
...
CHK INST_CHECK, 0
LD R1, R12, 0x04 -- Example instruction
MOV R5, R1
ADD R1, R5
CHK INST_CHECK, 1
ADD R1, R5
...
-- End of program
[FILL] 0x0000, 0x8000
-- Begin Redundancy table
LD R1, R12, 0x04 -- Redundant Instruction 0
ADD R1, R5 -- Redundant Instruction 1
Works w/o reliability features as of 6f1009b