AMCC PPC405 - Table 9-20. Extended Mnemonics for Mftb; Table 9-21. Extended Mnemonics for Mftb

AMCC Proprietary 268
Revision 1.02 - September 10, 2007
PPC405 Processor
mftb
Move From Time Base
Preliminary User’s Manual
mftb
Move From Time Base
TBRN ← TBRF
5:9
|| TBRF
0:4
(RT) ← (TBR(TBRN))
The contents of the time base register (TBR) specified by the TBRF field are placed into register RT. The following
table lists the TBRN and TBRF values.
If TBRN is a value other than those listed in the table, the results are boundedly undefined.
Registers Altered
•RT
Invalid Instruction Forms
• Reserved fields
• Invalid TBRF values
Programming Notes
The mnemonic mftb serves as both a hardware mnemonic and an extended mnemonic. The assembler recog-
nizes an mftb mnemonic having two operands as the hardware form; an mftb mnemonic having one operand is
recognized as the extended form.
The TBR number (TBRN) specified in the assembler language coding of the mftb instruction refers to a TBR
number listed in the preceding table. The assembler handles the unusual register number encoding to generate the
TBRF field.
Architecture Note
This instruction is part of the PowerPC Embedded Virtual Environment.
mftb RT, TBRN
31 RT TBRF 371
0 6 11 21 31
Table 9-20. Extended Mnemonics for mftb
Register
Mnemonic
Register Name
TBRN
TBRF Access
Decimal Hex
TBL Time Base Lower 268 0x10C 0x188 Read-only
TBU Time Base Upper 269 0x10D 0x1A8 Read-only
Table 9-21. Extended Mnemonics for mftb
Mnemonic Operands Function
Other Registers
Altered
mftb RT
Move the contents of TBL into RT.
Extended mnemonic for
mftb RT,TBL
mftbu RT
Move the contents of TBU into RT.
Extended mnemonic for
mftb RT,TBU