![Xilinx Virtex-II Pro PPC405 Скачать руководство пользователя страница 21](http://html1.mh-extra.com/html/xilinx/virtex-ii-pro-ppc405/virtex-ii-pro-ppc405_user-manual_3410279021.webp)
March 2002 Release
329
Virtex-II Pro™ Platform FPGA Documentation
1-800-255-7778
PPC405 Features
R
PowerPC Book-E Architecture
The PowerPC Book-E architecture extends the capabilities introduced in the PowerPC
embedded-environment architecture. Although not a PowerPC Book-E implementation,
many of the features available in the 32-bit subset of the PowerPC Book-E architecture are
available in the PPC405. The PowerPC Book-E architecture and the PowerPC embedded-
environment architecture differ in the following general ways:
•
64-bit addressing and 64-bit operands are available. Unlike 64-bit mode in the
PowerPC UISA, 64-bit support in PowerPC Book-E architecture is non-modal and
instead defines new 64-bit instructions and flags.
•
Real mode is eliminated, and the memory-management unit is active at all times. The
elimination of real mode results in the elimination of real-mode storage-attribute
registers.
•
Memory synchronization requirements are changed in the architecture and a
memory-barrier instruction is introduced.
•
A small number of new instructions are added to the architecture and several
instructions are removed.
•
Several SPR addresses and names are changed in the architecture, as are the
assignment and meanings of some bits within certain SPRs.
Embedded applications written for the PPC405 are compatible with PowerPC Book-E
implementations. Privileged software is, in general, not compatible, but the differences are
relatively minor. Software developers who are concerned with cross-compatibility of
privileged software between the PPC405 and PowerPC Book-E implementations should
refer to
PPC405 Features
The PPC405 processor core is an implementation of the PowerPC embedded-environment
architecture. The processor provides fixed-point embedded applications with high
performance at low power consumption. It is compatible with the PowerPC UISA. Much
of the PPC405 VEA and OEA support is also available in implementations of the PowerPC
Book-E architecture. Key features of the PPC405 include:
•
A fixed-point execution unit fully compliant with the PowerPC UISA:
-
32-bit architecture, containing thirty-two 32-bit general purpose registers (GPRs).
•
PowerPC embedded-environment architecture extensions providing additional
support for embedded-systems applications:
-
True little-endian operation
-
Flexible memory management
-
Multiply-accumulate instructions for computationally intensive applications
-
Enhanced debug capabilities
-
64-bit time base
-
3 timers: programmable interval timer (PIT), fixed interval timer (FIT), and
watchdog timer (All are synchronous with the time base)
•
Performance-enhancing features, including:
-
Static branch prediction
-
Five-stage pipeline with single-cycle execution of most instructions, including
loads and stores
-
Multiply-accumulate instructions
-
Hardware multiply/divide for faster integer arithmetic (4-cycle multiply, 35-cycle
divide)
-
Enhanced string and multiple-word handling
Содержание Virtex-II Pro PPC405
Страница 1: ...R Volume 2 a PPC405 User Manual Virtex II Pro Platform FPGA Developer s Kit March 2002 Release...
Страница 14: ...322 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation Preface R...
Страница 252: ...560 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 260: ...568 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...
Страница 562: ...870 www xilinx com March 2002 Release 1 800 255 7778 Virtex II Pro Platform FPGA Documentation R...