Filter
Top Products
Waivers and Implementation-Dependent Functionality E–5
E.2.1.2 Functions and Arguments for the DECchip 21064/21066/21068
The functions execute on a single (the current running) processor only and are described in
Table E–1.
• The OpenVMS Alpha MTPR_PERFMON instruction is called with a function code in
R16, a function-specific argument in R17, and status is returned in R0.
• The DIGITAL UNIX wrperfmon instruction is called with a function code in a0, a func-
tion specific argument in a1, and status is returned in v0.
• The Windows NT Alpha wrperfmon instruction is called with input parameters a0
through a3, as shown in Table E–1.
Table E–1: DECchip 21064/21066/21068 Performance Monitoring Functions
Function Register Usage Comments
Enable performance monitoring
Enable takes effect at the next IPL change
DIGITAL UNIX
Input: a0 = 1 Function code
a1 = 0 Argument
Output: v0 = 1 Success
v0 = 0 Failure (not generated)
OpenVMS Alpha
Input: R16 = 1 Function code
R17 = 0 Argument
Output: R0 = 1 Success
R0 = 0 Failure (not generated)
Windows NT Alpha
Input: a0 = 0 Select counter 0
a0 = 1 Select counter 1
a1 = 1 Enable selected counter
Disable performance monitoring
Disable takes effect at the next IPL change
DIGITAL UNIX
Input: a0 = 0 Function code
a1 = 0 Argument
Output: v0 = 1 Success
v0 = 0 Failure (not generated)
OpenVMS Alpha
Input: R16 = 0 Function code
R17 = 0 Argument
Output: R0 = 1 Success
R0 = 0 Failure (not generated)