
Table 
| Function Register Usage | Comments | 
Enable performance monitoring; start the counters from zero
| DIGITAL UNIX | 
 | 
 | 
| Input: | a0 = 7 | Function code value | 
| 
 | a1 = arg | Argument from Table  | 
| Output: | v0 = 1 | Success | 
| 
 | v0 = 0 | Failure (not generated) | 
| OpenVMS Alpha | 
 | 
 | 
| Input: | R16 = 7 | Function code value | 
| 
 | R17 = arg | Argument from Table  | 
| Output: | R0 = 1 | Success | 
| 
 | R0 = 0 | Failure (not generated) | 
Disable performance monitoring; do not reset counters
| DIGITAL UNIX | 
 | 
 | 
| Input: | a0 = 0 | Function code value | 
| 
 | a1 = arg | Argument from Table  | 
| Output: | v0 = 1 | Success | 
| 
 | v0 = 0 | Failure (not generated) | 
| OpenVMS Alpha | 
 | 
 | 
| Input: | R16 = 0 | Function code value | 
| 
 | R17 = arg | Argument from Table  | 
| Output: | R0 = 1 | Success | 
| 
 | R0 = 0 | Failure (not generated) | 
Select desired events (MUX_SELECT)
| DIGITAL UNIX | 
 | 
 | 
| Input: | a0 = 2 | Function code value | 
| 
 | a1 = arg | Argument from Table  | 
| Output: | v0 = 1 | Success | 
| 
 | v0 = 0 | Failure (not generated) | 
| OpenVMS Alpha | 
 | 
 | 
| Input: | R16 = 2 | Function code value | 
| 
 | R17 = arg | Argument from Table  | 
| Output: | R0 = 1 | Success | 
| 
 | R0 = 0 | Failure (not generated) | 
| 
 | 
 | 
 | 
Waivers and 
