MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 148

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

3.9.10 Implementation-Specific SPRs
3.9.10.1 EIE, EID, and NRI Special-Purpose Registers
3.9.10.2 Floating-Point Exception Cause Register (FPECR)
MPC555
USER’S MANUAL
Bit(s)
16:31
0:15
The MPC555 / MPC556 includes several implementation-specific SPRs that are not
defined by the PowerPC architecture. These registers can be accessed by supervisor-
level instructions only. These registers are listed in
The RCPU includes three implementation-specific SPRs to facilitate the software ma-
nipulation of the MSR[RI] and MSR[EE] bits. Issuing the mtspr instruction with one of
these registers as an operand causes the RI and EE bits to be set or cleared as shown
in
A read (mfspr) of any of these locations is treated as an unimplemented instruction,
resulting in a software emulation exception.
The FPECR is a 32-bit supervisor-level internal status and control register used by the
floating-point assist firmware envelope. It contains four status bits indicating whether
the result of the operation is tiny and whether any of three source operands are denor-
malized. In addition, it contains one control bit to enable or disable SIE mode. This reg-
ister must not be accessed by user code.
Table
/
MPC556
REVISION
VERSION
Name
3-17.
Table 3-16 Processor Version Register Bit Descriptions
A 16-bit number that identifies the version of the processor and of the PowerPC architec-
ture. MPC555 / MPC556 value is 0x0002.
A 16-bit number that distinguishes between various releases of a particular version. The
MPC555 / MPC556 value is 0x0020.
Table 3-17 EIE, EID, AND NRI Registers
SPR Number
(Decimal)
80
81
82
CENTRAL PROCESSING UNIT
Rev. 15 October 2000
Mnemonic
EID
NRI
EIE
MSR[EE]
Description
1
0
0
Table 3-2
MSR[RI]
1
1
0
and
Table
3-3.
MOTOROLA
3-26