ETC XPC755BRX350LD

Fact Sheet
MPC755
AND MPC745
MICROPROCESSORS
MPC755 and MPC745 microprocessors are high-performance, low-power, 32-bit
implementations of the PowerPC architecture, specially enhanced for embedded
applications. MPC755 and MPC745 microprocessors differ only in that the MPC755
features an enhanced, dedicated L2 cache interface with on-chip L2 tags. The MPC755
is a drop-in replacement for the award-winning MPC750 microprocessor and is
footprint- and user software code-compatible with the MPC7400 microprocessor with
AltiVec™ technology. The MPC745 is a drop-in replacement for the MPC740
microprocessor and is also footprint- and user software code-compatible with Motorola
G2 microprocessors. MPC755/MPC745 microprocessors provide on-chip debug support
and are fully JTAG-compliant.
SUPERSCALAR MICROPROCESSOR
MPC755 and MPC745 microprocessors are superscalar,
capable of issuing three instructions per clock cycle (two
instructions + branch) into six independent execution units:
• Two integer units
• Load/store unit
• Double-precision floating-point unit
• System register unit
• Branch processing unit
MOTOROLA MPC755/MPC745 BLOCK DIAGRAM
Completion
Unit
Integer
Unit
Dispatch
Unit
Gen
Gen
Reg Rename
File
Load/
Store
Unit
D MMU
Data Cache
FPU
Reg
File
Floating
Point
Unit
I MMU
Inst. Cache
Bus Interface Unit
32-bit Address
Branch
Unit
32-/64-bit Data
System Bus
L2 Tags
L2 Cache
Port (755 only)
FSRAM
MPC745
MPC755
300-350 MHz
300-400 MHz
300 and 350 MHz
300, 350 and 400 MHz
x3, x3.5, x4, x4.5, x5, x5.5,
x6, x6.5, x7, x7.5, x8, x10
x3, x3.5, x4, x4.5, x5, x5.5,
x6, x6.5, x7, x7.5, x8, x10
32/64-bit
32/64-bit
3 (2 + Branch)
3 (2 + Branch)
L1 Cache
32 KB instruction
32 KB data
L2 Cache
—
32 KB instruction
32 KB data
256, 512 KB
1 MB
Core-to-L2 Frequency
Typical/Maximum
Power Dissipation
—
1:1, 1.5:1, 2:1, 2.5:1, 3:1
TBD
TBD
Die Size
51 mm2
51 mm2
Package
255 PBGA
360 PBGA
Process
0.22µ 5LM
0.22µ 5LM
Voltage
CPU Speeds – Internal
CPU Bus Dividers
Bus Interface
Instructions per Clock
1.8/3.3V I/O, 2.0V internal
1.8/3.3V I/O, 2.0V internal
SPECint95 (estimated)
15.7 @ 350 MHz
18.1 @ 400 MHz
SPECfp95 (estimated)
11.6 @ 350 MHz
12.3 @ 400 MHz
641 MIPS @ 350 MHz
733 MIPS @ 400 MHz
Integer(2), Floating-Point, Branch,
Load/Store, System Register
Integer(2), Floating-Point, Branch,
Load/Store, System Register
Other Performance
Execution Units
The ability to execute multiple instructions in parallel, the ability to pipeline instructions,
and the use of simple instructions with rapid execution times yields maximum efficiency
and throughput for MPC755 and MPC745 systems.
POWER MANAGEMENT
The MPC755 and MPC745 microprocessors feature a low-power 2.0V design with three
power-saving user-programmable modes—doze, nap, and sleep—which progressively
reduce the power drawn by the processor.
These low-power microprocessors offer dynamic power management to selectively
activate functional units as they are needed by the executing instructions. Both
microprocessors also provide a thermal assist unit and instruction cache throttling for
software-controllable thermal management.
MPC755/MPC745 microprocessors
contain separate memory
management units (MMUs) for
instructions and data, supporting
4 petabytes (252) of virtual memory
and 4 GB (232) of physical memory.
Both feature eight instruction block
address translation (iBAT) and
eight data block address
translation (dBAT) registers. Access
privileges and memory protection
are controlled on block or page
granularities. Large, 128-entry
translation lookaside buffers (TLBs)
provide efficient physical address
translation and support for virtualmemory management on both
page- and variable-sized blocks.
Both hardware and software
tablewalks are provided for the TLBs.
FLEXIBLE BUS INTERFACE
MPC755/MPC745 microprocessors have a 64-bit data bus
with 32-bit mode and a 32-bit address bus. Support is
included for burst, split, and pipelined transactions. The
interface provides snooping for data cache coherency.
Both microprocessors maintain MEI coherency protocol in
hardware, allowing access to system memory for
additional caching bus masters, such as DMA devices.
CONTACT INFORMATION
Motorola offers user’s manuals, application notes, and
sample code for all of its processors. Local support for
these products is also provided. This information can be
found at: http://motorola.com/smartnetworks
CACHE AND MMU SUPPORT
The MPC755/MPC745 microprocessors have separate 32 KB, physically addressed
instruction and data caches. Both caches can be locked in part or whole to provide
storage of critical data, key performance algorithms, or code loops for fast response
time. The MPC755 microprocessor’s dedicated L2 cache interface with on-chip L2 tags
(up to 1 MB) features support for direct-mapped SRAM mode, physically mapped SRAM
mode, a fast (typically 1/2 core speed) interface to memory, instruction-only or data-only
modes, and parity checking on both L2 address and data.
For all other inquiries about Motorola products, please
contact the Motorola Customer Response Center at:
Phone: 800-521-6274 or
http://motorola.com/semiconductors
MOTOROLA and the Stylized M Logo are registered in the U.S. Patent and Trademark Office. All other product or
service names are the property of their respective owners.
© Motorola, Inc. 2002.
MPC755fact/rev.2