mhpmcounter8

Machine Hardware Performance Counter 8

Programmable hardware performance counter.

The hpmcounter8 CSR is a read-only shadow of this CSR. Access to hpmcounter8 is controlled with mcounteren.HPM8 <%- if ext?(:S) -%> , scounteren.HPM8 <%- if ext?(:H) -%> , and hcounteren.HPM8 <%- end -%> <%- end -%> as follows:

<%- if ext?(:H) -%>

mcounteren.HPM8

scounteren.HPM8

hcounteren.HPM8

hpmcounter8 behavior

S-mode

U-mode

VS-mode

VU-mode

0

-

-

IllegalInstruction

IllegalInstruction

IllegalInstruction

IllegalInstruction

1

0

0

read-only

IllegalInstruction

VirtualInstruction

VirtualInstruction

1

1

0

read-only

read-only

VirtualInstruction

VirtualInstruction

1

0

1

read-only

IllegalInstruction

read-only

VirtualInstruction

1

1

1

read-only

read-only

read-only

read-only

<%- elsif ext?(:S) -%>

mcounteren.HPM8

scounteren.HPM8

hpmcounter8 behavior

S-mode

U-mode

0

-

IllegalInstruction

IllegalInstruction

1

0

read-only

IllegalInstruction

1

1

read-only

read-only

<%- else -%>

mcounteren.HPM8

hpmcounter8 behavior

U-mode

0

IllegalInstruction

1

read-only

<%- end -%>

Attributes

Requirement

Sm

Defining extensions

Sm

Machine mode

CSR Address

0xb08

Length

64-bit

Privilege Mode

M

Format

mhpmcounter8 format
Figure 1. mhpmcounter8 format

Field Summary

Name Location Type Reset Value

mhpmcounter8.COUNT

63:0

[when,"HPM_COUNTER_EN[8]"] RW-H

[when,"!(HPM_COUNTER_EN[8])"] RO

UNDEFINED_LEGAL

Fields

COUNT

Location

63:0

Description

Performance counter for event selected in mhpmevent8.EVENT.

Increments every time event occurs unless:

  • mcountinhibit.HPM8 <%- if ext?(:Smcdeleg) -%>or its alias scountinhibit.HPM8<%- end -%> is set <%- if ext?(:Sscofpmf) -%>

  • mhpmevent8.MINH is set and the current privilege level is M <%- if ext?(:S) -%>

  • mhpmevent8.SINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent8.SINH<%- end -%> is set and the current privilege level is (H)S <%- end -%> <%- if ext?(:U) -%>

  • mhpmevent8.UINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent8.UINH<%- end -%> is set and the current privilege level is U <%- end -%> <%- if ext?(:H) -%>

  • mhpmevent8.VSINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent8.VSINH<%- end -%> is set and the current privilege level is VS

  • mhpmevent8.VUINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent8.VUINH<%- end -%> is set and the current privilege level is VU <%- end -%> <%- end -%>

Unimplemented performance counter. Must be read-only 0 (access does not cause trap).

Type

RW-H

RO

Reset value

UNDEFINED_LEGAL

Software read

This CSR may return a value that is different from what is stored in hardware.

if (HPM_COUNTER_EN[8]) {
  return read_hpm_counter(8);
} else {
  return 0;
}