---
name: "pmc.dmc-620"
section: "3"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/pmc.dmc-620"
---

# pmc.dmc-620(3)

measure the Arm DMC-620 Dynamic Memory Controller performance counter events.

## NAME

**pmc.dmc-620** – measure the Arm DMC-620 Dynamic Memory Controller performance counter events.

## LIBRARY

library “libpmc”

## SYNOPSIS

**#include \<pmc.h\>**

## DESCRIPTION

DMC-620 PMU counters may be configured to count any one of a defined set of hardware events.

Arm CoreLink DMC-620 Dynamic Memory Controller performance counters are documented in “Revision: r0p0”, *ARM CoreLink DMC-620 Dynamic Memory Controller Technical Reference Manual*, ARM Limited, 2017.

### PMC Capabilities

DMC-620 PMU counters support the following capabilities:

| | |
| --- | --- |
| **Capability** | *Support* |
| PMC\_CAP\_CASCADE | No |
| PMC\_CAP\_EDGE | No |
| PMC\_CAP\_INTERRUPT | Yes |
| PMC\_CAP\_INVERT | Yes |
| PMC\_CAP\_READ | Yes |
| PMC\_CAP\_PRECISE | No |
| PMC\_CAP\_SYSTEM | Yes |
| PMC\_CAP\_TAGGING | No |
| PMC\_CAP\_THRESHOLD | Yes |
| PMC\_CAP\_USER | No |
| PMC\_CAP\_WRITE | Yes |

### Event Qualifiers

Event specifiers for these PMCs support the following common qualifiers:

- inc=*value*

  Two-bit value that controls direction of count for PMC. Behavior depend on selected event.

- inv

  Invert the sense of comparison.

- match=*value*

  Count only events matched by *value.*

- mask=*qualifier*

  Allow to apply *qualifier* mask to compared *value*.

### Class Name Prefix

These PMCs use a class name prefix of “DMC620\_CD2\_” or “DMC620\_C\_”.

### Event Specifiers

The following PMC events are available:

| |
| --- |
| **clkdiv2\_cycle\_count** |
| **clkdiv2\_allocate** |
| **clkdiv2\_queue\_depth** |
| **clkdiv2\_waiting\_for\_wr\_data** |
| **clkdiv2\_read\_backlog** |
| **clkdiv2\_waiting\_for\_mi** |
| **clkdiv2\_hazard\_resolution** |
| **clkdiv2\_enqueue** |
| **clkdiv2\_arbitrate** |
| **clkdiv2\_lrank\_turnaround\_activate** |
| **clkdiv2\_prank\_turnaround\_activate** |
| **clkdiv2\_read\_depth** |
| **clkdiv2\_write\_depth** |
| **clkdiv2\_highhigh\_qos\_depth** |
| **clkdiv2\_high\_qos\_depth** |
| **clkdiv2\_medium\_qos\_depth** |
| **clkdiv2\_low\_qos\_depth** |
| **clkdiv2\_activate** |
| **clkdiv2\_rdwr** |
| **clkdiv2\_refresh** |
| **clkdiv2\_training\_request** |
| **clkdiv2\_t\_mac\_tracker** |
| **clkdiv2\_bk\_fsm\_tracker** |
| **clkdiv2\_bk\_open\_tracker** |
| **clkdiv2\_ranks\_in\_pwr\_down** |
| **clkdiv2\_ranks\_in\_sref** |
| **clk\_cycle\_count** |
| **clk\_request** |
| **clk\_upload\_stall** |

## SEE ALSO

[pmc(3)](/pmc/3.md), [pmc.amd(3)](/pmc.amd/3.md), [pmc.atom(3)](/pmc.atom/3.md), [pmc.core(3)](/pmc.core/3.md), [pmc.core2(3)](/pmc.core2/3.md), [pmc.corei7(3)](/pmc.corei7/3.md), [pmc.corei7uc(3)](/pmc.corei7uc/3.md), [pmc.iaf(3)](/pmc.iaf/3.md), [pmc.soft(3)](/pmc.soft/3.md), [pmc.tsc(3)](/pmc.tsc/3.md), [pmc.westmere(3)](/pmc.westmere/3.md), [pmc.westmereuc(3)](/pmc.westmereuc/3.md), [pmc\_cpuinfo(3)](/pmc_cpuinfo/3.md), [pmclog(3)](/pmclog/3.md), [hwpmc(4)](/hwpmc/4.md)

## HISTORY

The **pmc** library first appeared in FreeBSD 6.0.\
 The **pmc.dmc-620** driver was added in FreeBSD 14.0.

## AUTHORS

The library “libpmc” library was written by Joseph Koshy ⟨*jkoshy@FreeBSD.org*⟩. Oleksandr Rybalko ⟨*ray@FreeBSD.org*⟩.\
 The DMC-620 PMU driver was sponsored by Ampere Computing LLC. This manual page was written by Oleksandr Rybalko ⟨*ray@FreeBSD.org*⟩.