RISC-V scountovf CSR Register

Address 0xDA0Privilege SupervisorAccess RO / XLENSupervisor counters and overflow CSRs

scountovf at 0xDA0 is a supervisor read-only CSR reporting counter overflow state.

Related Search Terms

scountovf CSR scountovf 0xDA0 counter overflow CSR supervisor counter overflow LCOFI overflow state RISC-V scountovf

Bit Overview

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bit 3 = only bit 3; bits 12..11 = bits 12 down to 11

MSBLSB

VALUE63:0RO

Field Map

Understand scountovf By Bit Fields

1 key fields

XLEN-1:0

VALUE

Full register value of scountovf; 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 XLEN-1:0) — Full register value of scountovf; 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 scountovf; 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.

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Official Basis & Search Notes

scountovf is a RO CSR in supervisor counters and overflow csrs at 0xDA0. Check privilege and implemented extensions before interpreting its bit fields.

scountovf address, lowest access privilege, and access class are checked against the official CSR table: 0xDA0, Supervisor, RO.

scountovf belongs to supervisor counter state; read it with counteren, countinhibit, and overflow-related CSRs.

This is a read-only CSR; do not write it. Ignore reserved or WPRI field values on reads, and preserve unchanged fields when writing writable CSRs.

RISC-V Privileged Architecture Manual RISC-V Unprivileged ISA Manual

What To Check First When Reading This CSR

- First confirm that the current hart implements scountovf; unimplemented or insufficiently privileged accesses raise an illegal-instruction exception.
- Use address 0xDA0 and the lowest access privilege (Supervisor) 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

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

Put It Back Into A Real Flow

Read scountovf to obtain hardware or runtime state.

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

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

FAQ

Can scountovf be accessed from any privilege level?

Do not decide from the CSR name alone. The official CSR address encoding and tables define the lowest access privilege; this entry records scountovf as Supervisor. Access with insufficient privilege or to an unimplemented CSR raises an illegal-instruction exception.

What is easiest to miss when using scountovf?

scountovf is read-only. Treat it as an observation point, do not try to write it, and do not depend on fixed values for reserved or WPRI fields.