[TASK] Add Zb* in User Manual

Created by: ASintzoff

Is there an existing CVA6 task for this?

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Task Description

Write User Manual chapter describing Zb* instructions (bitmanip extensions).

Required Changes

Add chapter in User Manual.

• Split the specification in 4 files (one for each group: Zba, Zbb, Zbc, Zbs) to ease definition of configurations with some of the groups: RISCV_Instructions_RVZba.rst, RISCV_Instructions_RVZbb.rst, RISCV_Instructions_RVZbc.rst, RISCV_Instructions_RVZbs.rst

Current Status

RTL available

Risks

No response

Prerequisites

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KPI (KEY Performance Indicators)

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Description of Done

PR merged

Associated PRs

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