mhpmcounter4

Machine Hardware Performance Counter 4

Programmable hardware performance counter.

The hpmcounter4 CSR is a read-only shadow of this CSR. Access to hpmcounter4 is controlled with mcounteren.HPM4 <%- if ext?(:S) -%> , scounteren.HPM4 <%- if ext?(:H) -%> , and hcounteren.HPM4 <%- end -%> <%- end -%> as follows:

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

mcounteren.HPM4

scounteren.HPM4

hcounteren.HPM4

hpmcounter4 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.HPM4

scounteren.HPM4

hpmcounter4 behavior

S-mode

U-mode

0

-

IllegalInstruction

IllegalInstruction

1

0

read-only

IllegalInstruction

1

1

read-only

read-only

<%- else -%>

mcounteren.HPM4

hpmcounter4 behavior

U-mode

0

IllegalInstruction

1

read-only

<%- end -%>

Attributes

Requirement

Sm

Defining extensions

Sm

Machine mode

CSR Address

0xb04

Length

64-bit

Privilege Mode

M

Format

mhpmcounter4 format
Figure 1. mhpmcounter4 format

Field Summary

Name Location Type Reset Value

mhpmcounter4.COUNT

63:0

[when,"HPM_COUNTER_EN[4]"] RW-H

[when,"!(HPM_COUNTER_EN[4])"] RO

UNDEFINED_LEGAL

Fields

COUNT

Location

63:0

Description

Performance counter for event selected in mhpmevent4.EVENT.

Increments every time event occurs unless:

  • mcountinhibit.HPM4 <%- if ext?(:Smcdeleg) -%>or its alias scountinhibit.HPM4<%- end -%> is set <%- if ext?(:Sscofpmf) -%>

  • mhpmevent4.MINH is set and the current privilege level is M <%- if ext?(:S) -%>

  • mhpmevent4.SINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent4.SINH<%- end -%> is set and the current privilege level is (H)S <%- end -%> <%- if ext?(:U) -%>

  • mhpmevent4.UINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent4.UINH<%- end -%> is set and the current privilege level is U <%- end -%> <%- if ext?(:H) -%>

  • mhpmevent4.VSINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent4.VSINH<%- end -%> is set and the current privilege level is VS

  • mhpmevent4.VUINH <%- if ext?(:Ssccfg) -%>or its alias hpmevent4.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[4]) {
  return read_hpm_counter(4);
} else {
  return 0;
}