Glossary-2
MPC8240 Integrated Processor User’s Manual
Cache block. The cacheable unit for a PowerPC processor. The size of a
cache block may vary among processors. For the 603e, it is one
cache line (8 words).
Cache coherency. Caches are coherent if a processor performing a read from
its cache is supplied with data corresponding to the most recent value
written to memory or to another processor’s cache.
Cast-outs. Cache block that must be written to memory when a snoop miss
causes the least recently used block with modified data to be
replaced.
Context synchronization. Context synchronization is the result of specific
instructions (such as sc or rfi) or when certain events occur (such as
an exception). During context synchronization, all instructions in
execution complete past the point where they can produce an
exception; all instructions in execution complete in the context in
which they began execution; all subsequent instructions are fetched
and executed in the new context.
Copy-back operation. A cache operation in which a cache line is copied
back to memory to enforce cache coherency. Copy-back operations
consist of snoop push-out operations and cache cast-out operations.
Denormalized number. A nonzero floating-point number whose exponent
has a reserved value, usually the format's minimum, and whose
explicit or implicit leading significand bit is zero.
Direct-store segment access. An access to an I/O address space. The 603
defines separate memory-mapped and I/O address spaces, or
segments, distinguished by the corresponding segment register T bit
in the address translation logic of the 603. If the T bit is cleared, the
memory reference is a normal memory-mapped access and can use
the virtual memory management hardware of the 603. If the T bit is
set, the memory reference is a direct-store access.
Exception. An unusual or error condition encountered by the processor that
results in special processing.
Exception handler. A software routine that executes when an exception
occurs. Normally, the exception handler corrects the condition that
caused the exception, or performs some other meaningful task (such
as aborting the program that caused the exception). The addresses of
the exception handlers are defined by a two-word exception vector
that is branched to automatically when an exception occurs.
D
E
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...