mftbu

Move From Timebase Upper

mftbu RT

Reads the upper 32 bits of the Timebase (32-bit implementations).

Details

The mftbu instruction moves the upper 32 bits of the Time Base register into a general-purpose register.

Pseudocode Operation

RT ← TBU

Programming Note

Use mftbu to capture the high-order bits of the timebase for timestamping or performance measurement. Ensure that your application accounts for potential discrepancies between the upper and lower 32-bit reads due to timebase overflow.

Example

mftbu r3

Encoding

Binary Layout
31
0
RT
6
269
11
371
21
/
31
 
Format XFX-form
Opcode 0x7C0002E7
Extension Base
Registers Altered TBU

Operands

  • RT
    Target