Zicsr: CSR Access

Ratified 2019-04 · version 2.0.0

Instructions to read, write and atomically modify control and status registers, the interface to most machine state.

Typical use: Any code that reads or writes CSRs

Dependencies

Mnemonic	Name	Encoding	Match	Mask
`CSRRC`	Atomic Read and Clear Bits in CSR	`-----------------011-----1110011`	`0x3073`	`0x707f`
`CSRRCI`	Atomic Read and Clear Bits in CSR with Immediate	`-----------------111-----1110011`	`0x7073`	`0x707f`
`CSRRS`	Atomic Read and Set Bits in CSR	`-----------------010-----1110011`	`0x2073`	`0x707f`
`CSRRSI`	Atomic Read and Set Bits in CSR with Immediate	`-----------------110-----1110011`	`0x6073`	`0x707f`
`CSRRW`	Atomic Read/Write CSR	`-----------------001-----1110011`	`0x1073`	`0x707f`
`CSRRWI`	Atomic Read/Write CSR Immediate	`-----------------101-----1110011`	`0x5073`	`0x707f`