MC68030RC40C Freescale Semiconductor, MC68030RC40C Datasheet - Page 378

• Manufacturer Part Number: MC68030RC40C
• Description: IC MPU 32BIT ENHANCED 128-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68030RC40C

• Processor Type: M680x0 32-Bit
• Speed: 40MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 128-PGA
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 40MHz
• Instruction Set Architecture: RISC
• Supply Voltage 1 (typ): 5V
• Operating Supply Voltage (max): 5.25V
• Operating Supply Voltage (min): 4.75V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Mounting: Through Hole
• Pin Count: 128
• Package Type: PGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Lead Free Status / Rohs Status: Compliant

MOTOROLA
that run in the UNIX (r) environment have similar requirements for memory.
tection and maps the entire virtual operating system, physical
across the user/supervisor boundary. All the operating system has to do when
creating the address table for a new task is to set the first upper level table
To solve the problem of accounting for virtual memory areas assigned to a
these areas. When a valid descriptor points to a given virtual address page,
this 8K-byte page of memory has been allocated. This scheme provides areas
of memory that are multiples of the 8K-byte page size. Due to the 8K gran-
The operating system primitive GetVirtual allocates virtual memory space
for tasks. The input parameter is a block size, in bytes; GetVirtual returns the
virtual address for the new block. GetVirtual first checks that the requested
size to its maximum. If this does not provide the space, GetVirtual returns
with a valid page descriptor. The status (indicated by a software flag in the
When the status of an invalid descriptor indicates that a page image must
for this routine is the invalid descriptor, which contains the disk address of
the page image. Before returning, SwaplnPage replaces the invalid descriptor
with a valid page descriptor that contains the page address. The page is now
ical memory areas. This scheme avoids the requirement for extra lookup
levels or pointer manipulations during a task switch to furnish correct access
entry to point to the common page table of the supervisor.
user task, the operating system uses the existing translation tables to identify
ularity, this scheme would be inadequate for tasks that continually request
and return virtual memory space. As a result, some other technique would
be used (perhaps auxiliary tables to show virtual space availability). The tasks
in this system seldom request additional memory space; any request made
is for a large area. This scheme suffices. The application programs and utilities
size is not too large. Then it scans the translation tables looking for an un-
allocated virtual memory area large enough to hold the requested block. If
it does not find enough space, GetVirtual attempts to increase the page table
an error indication. When the routine finds enough virtual space for the block,
it sets the page descriptors for the block to virgin status (invalid, but allo-
cated). When these pages are first used, a page fault is generated. The op-
erating system allocates a page frame for the page and replaces the descriptor
is required.
be read in, primitive SwaplnPage, reads in the image. The input parameter
invalid descriptor) tells the operating system that the paging device does not
have a page image for this page; no read operation from the paging device
ready for use.
MC68030 USER'S MANUAL
I/0,
and phys-
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