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PowerPC Architecture Compliance
7-6
MPC801 USER’S MANUAL
MOTOROLA
7
7.2.3.9 ENFORCE IN-ORDER EXECUTION OF I/O (eieio)
When executing an
eieio
instruction, the load/store unit waits until all previous accesses
have terminated before issuing cycles related to load/store instructions that follow
eieio
.
7.2.4 Timebase
A description of the timebase register can be found in
Section 12 System Interface Unit
and in
Section 5 Clocks and Power Control
.
7.3 POWERPC OPERATING ENVIRONMENT ARCHITECTURE (BOOK III)
The MPC801 has an internal memory space that includes memory-mapped control registers
and memory that is used by various modules on the chip. This memory is part of the main
memory as seen by the core but cannot be accessed by any external system master.
7.3.1 The Branch Processor
7.3.1.1 BRANCH PROCESSOR REGISTERS
The branch processor registers consist of the machine state and processor version
registers.
7.3.1.1.1 Machine State Register.
The floating-point exception mode is ignored by the
MPC801. The IP bit initial state after reset is set as programmed by the reset configuration
as specified by the
Section 12 System Interface Unit
.
7.3.1.1.2 Processor Version Register.
In the processor version register (PVR), the value
of the version field is x’0050’. In addition, the value of the revision field is x’0000’ and it is
incremented each time the software distinguishes between the core revisions.
7.3.1.2 BRANCH PROCESSOR INSTRUCTIONS
The core implements all the branch processor instructions defined in PowerPC
User
Instruction Set Architecture Book I For details about the performance of various
instructions, see Table 8-1 of this manual.
7.3.2 The Fixed-Point Processor
7.3.2.1 SPECIAL-PURPOSE REGISTERS
The special-purpose registers consist of the unsupported and added registers.
7.3.2.1.1 Unsupported Registers.
The following registers are not supported by the
MPC801. Refer to
Section 7.3.3 Storage Model
for more details.
SDR 1
IBAT2U
DBAT1U
IBAT0L
IBAT3L
DBAT2L
EAR
IBAT2L
DBAT1L
IBAT1U
DBAT0U
DBAT3U
IBAT0U
IBAT3U
DBAT2U
IBAT1L
DBAT0L
DBAT3L