mstatush

Machine Status High

The mstatus register tracks and controls the hart’s current operating state.

Attributes

Defining Extension	* Sm, version >= 1.12
CSR Address	0x310
Length	32-bit
Privilege Mode	M

Defining Extension

* Sm, version >= 1.12

CSR Address

0x310

Length

32-bit

Privilege Mode

Format

Figure 1. mstatush format

Field Summary

Name	Location	Type	Reset Value
mstatush.MDT	10	RW-H	UNDEFINED_LEGAL
mstatush.MPV	7	RW-H	UNDEFINED_LEGAL
mstatush.GVA	6	RW-H	0
mstatush.MBE	5	[when,"M_MODE_ENDIANNESS == "dynamic""] RW [when,"M_MODE_ENDIANNESS != "dynamic""] RO	UNDEFINED_LEGAL
mstatush.SBE	4	[when,"S_MODE_ENDIANNESS == "dynamic""] RW [when,"S_MODE_ENDIANNESS != "dynamic""] RO	UNDEFINED_LEGAL

Name

Location

Type

Reset Value

mstatush.MDT

RW-H

UNDEFINED_LEGAL

mstatush.MPV

RW-H

UNDEFINED_LEGAL

mstatush.GVA

RW-H

mstatush.MBE

[when,"M_MODE_ENDIANNESS == "dynamic""] RW

[when,"M_MODE_ENDIANNESS != "dynamic""] RO

UNDEFINED_LEGAL

mstatush.SBE

[when,"S_MODE_ENDIANNESS == "dynamic""] RW

[when,"S_MODE_ENDIANNESS != "dynamic""] RO

UNDEFINED_LEGAL

Fields

`MDT`

Location: 10
Description: Machine Disable Trap

Written to 1 when entering M-mode from an exception/interrupt. When returning via an MRET instruction, the bit is written to 0. On reset in set to 1, and software should write it to 0 when boot sequence is done. When mstatush.MDT=1, direct write by CSR instruction cannot set mstatus.MIE to 1.

Type: RW-H
Reset value: UNDEFINED_LEGAL

`MPV`

Location: 7
Description: Machine Previous Virtualization mode

Written with the prior virtualization mode when entering M-mode from an exception/interrupt. When returning via an MRET instruction, the virtualization mode becomes the value of MPV unless MPP=3, in which case the virtualization mode is always 0. Can also be written by software.

Type: RW-H
Reset value: UNDEFINED_LEGAL

`GVA`

Location: 6
Description: Guest Virtual Address

When a trap is taken and a guest virtual address is written into mtval, GVA is set. When a trap is taken and a guest virtual address is written into mtval, GVA is cleared.

Type: RW-H
Reset value: 0

`MBE`

Location: 5
Description: see mstatus.MBE
Type

Reset value: UNDEFINED_LEGAL

`SBE`

Location: 4
Description: see mstatus.SBE
Type

Reset value: UNDEFINED_LEGAL