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CSR Bit Fields

RISC-V hpmcounter29h CSR Register

Address 0xC9DPrivilege UserAccess RO / RV32 high-half / 32-bitUser counters and performance-monitoring CSRs

hpmcounter29h is the RV32 high-half CSR for the corresponding user hardware performance counter.

Bit Overview
bit 3 = only bit 3; bits 12..11 = bits 12 down to 11
MSBLSB
Reserved63:32VALUE31:0RO
Field Map

Understand hpmcounter29h By Bit Fields

1 key fields
31:0

VALUE

RO

Full register value of hpmcounter29h; bits not split out here follow the relevant extension or privileged specification, and reserved or WPRI fields should be preserved when writing other fields and ignored on reads.

VALUE (bits 31:0) — Full register value of hpmcounter29h; bits not split out here follow the relevant extension or privileged specification, and reserved or WPRI fields should be preserved when writing other fields and ignored on reads.

What This Field Controls

  • - Full register value of hpmcounter29h; bits not split out here follow the relevant extension or privileged specification, and reserved or WPRI fields should be preserved when writing other fields and ignored on reads.

Common Values

This field is better understood together with surrounding context than as a fixed memorized enumeration.

↗Open Official Manual

What To Check First When Reading This CSR

  • - First confirm that the current hart implements hpmcounter29h; unimplemented or insufficiently privileged accesses raise an illegal-instruction exception.
  • - Use address 0xC9D and the lowest access privilege (User) to decide whether software may read it directly.
  • - Do not assume fixed values for reserved, WARL, or WLRL bits; interpret the value according to the specification and implementation.

Risk Checks Before Writing

  • - hpmcounter29h is a read-only CSR; writes raise an illegal-instruction exception or are disallowed by the implementation.

Put It Back Into A Real Flow

1

Read hpmcounter29h to obtain hardware or runtime state.

2

Interpret the returned value according to the field descriptions and do not attempt to write it back.

3

If reading fails at the current privilege level, handle the illegal-instruction exception path.