timeh

High-half timer for RDTIME Instruction

This CSR does not exist, and access will cause an IllegalInstruction exception.

Shadow of the memory-mapped M-mode CSR mtimeh.

Privilege mode access is controlled with mcounteren.TM, scounteren.TM, and hcounteren.TM as follows:

mcounteren.TM	scounteren.TM	scounteren.TM	time behavior
S-mode	U-mode	VS-mode	VU-mode
0	-	-	`Illegal Instruction`	`Illegal Instruction`	`Illegal Instruction`	`Illegal Instruction`
1	0	0	read-only	`Illegal Instruction`	`Illegal Instruction`	`Illegal Instruction`
1	1	0	read-only	read-only	`Illegal Instruction`	`Illegal Instruction`
1	0	1	read-only	`Illegal Instruction`	read-only	`Illegal Instruction`
1	1	1	read-only	read-only	read-only	read-only

mcounteren.TM

scounteren.TM

time behavior

S-mode

U-mode

VS-mode

VU-mode

Illegal Instruction

read-only

Illegal Instruction

read-only

Illegal Instruction

read-only

Illegal Instruction

read-only

Illegal Instruction

read-only

Attributes

CSR Address	0xc81
Defining extension	Zicntr, version >= Zicntr@2.0.0
Length	32-bit
Privilege Mode	U

CSR Address

0xc81

Defining extension

Zicntr, version >= Zicntr@2.0.0

Length

32-bit

Privilege Mode

Format

Figure 1. timeh format

Field Summary

Name Location Type Reset Value

Name	Location	Type	Reset Value
`COUNT`	31:0	RO-H	UNDEFINED_LEGAL

COUNT

31:0

RO-H

UNDEFINED_LEGAL

Fields

`COUNT`

Location: timeh[31:0]
Description: Reports the most significant 32 bits of the current wall-clock time from the timer device.
Type

RO-H	Read-Only with Hardware update Writes are ignored. Reads reflect a value dynamically generated by hardware.

Reset value: UNDEFINED_LEGAL

Software read

This CSR may return a value that is different from what is stored in hardware.

Pruned
Original

if (%%LINK%func;mode;mode%%() == PrivilegeMode::S) {
  if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::U) {
  if (%%LINK%csr_field;misa.S;CSR[misa].S%% == 1'b1) {
    if ((%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% & %%LINK%csr_field;scounteren.TM;CSR[scounteren].TM%%) == 1'b0) {
      %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
    }
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::VS) {
  if (%%LINK%csr_field;hcounteren.TM;CSR[hcounteren].TM%% == 1'b0 && %%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b1) {
    %%LINK%func;raise;raise%%(ExceptionCode::VirtualInstruction, %%LINK%func;mode;mode%%(), $encoding);
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::VU) {
  if (%%LINK%csr_field;hcounteren.TM;CSR[hcounteren].TM%% & %%LINK%csr_field;scounteren.TM;CSR[scounteren].TM%%) == 1'b0) && (%%LINK%csr_field;mcounteren.IR;CSR[mcounteren].IR%% == 1'b1 {
    %%LINK%func;raise;raise%%(ExceptionCode::VirtualInstruction, %%LINK%func;mode;mode%%(), $encoding);
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
}
return %%LINK%func;read_mtime;read_mtime%%()[63:32];

if (!TIME_CSR_IMPLEMENTED) {
  %%LINK%func;unimplemented_csr;unimplemented_csr%%($encoding);
}
if (%%LINK%func;mode;mode%%() == PrivilegeMode::S) {
  if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::U) {
  if (%%LINK%csr_field;misa.S;CSR[misa].S%% == 1'b1) {
    if ((%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% & %%LINK%csr_field;scounteren.TM;CSR[scounteren].TM%%) == 1'b0) {
      %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
    }
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::VS) {
  if (%%LINK%csr_field;hcounteren.TM;CSR[hcounteren].TM%% == 1'b0 && %%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b1) {
    %%LINK%func;raise;raise%%(ExceptionCode::VirtualInstruction, %%LINK%func;mode;mode%%(), $encoding);
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
} else if (%%LINK%func;mode;mode%%() == PrivilegeMode::VU) {
  if (%%LINK%csr_field;hcounteren.TM;CSR[hcounteren].TM%% & %%LINK%csr_field;scounteren.TM;CSR[scounteren].TM%%) == 1'b0) && (%%LINK%csr_field;mcounteren.IR;CSR[mcounteren].IR%% == 1'b1 {
    %%LINK%func;raise;raise%%(ExceptionCode::VirtualInstruction, %%LINK%func;mode;mode%%(), $encoding);
  } else if (%%LINK%csr_field;mcounteren.TM;CSR[mcounteren].TM%% == 1'b0) {
    %%LINK%func;raise;raise%%(ExceptionCode::IllegalInstruction, %%LINK%func;mode;mode%%(), $encoding);
  }
}
return %%LINK%func;read_mtime;read_mtime%%()[63:32];