MC68030FE20C Freescale Semiconductor, MC68030FE20C Datasheet - Page 354

• Manufacturer Part Number: MC68030FE20C
• Description: IC MPU 32BIT ENHANCED 132-CQFP
• Manufacturer: Freescale Semiconductor

Specifications of MC68030FE20C

• Processor Type: M680x0 32-Bit
• Speed: 20MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 132-CQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -

MOTOROLA
Table Address
Limit
Descriptor Type (DT)
Unused
to ones ($7FFF in the word containing both fields), or the L/U bit is set and
the limit field is cleared ($8000 in that word).
the first level of the translation table identified by the root pointer. The
$0 INVALID
$1
$2 VALID 4 BYTE
$3 VALID 8 BYTE
table address field is the offset used to calculate the physical address for
the page descriptor. The table address field can contain zero (for zero
Specifies a maximum or minimum value for the index to be used at the
suppress the limit function, the L/U bit is cleared and the limit field is set
Specifies the type of descriptor contained in either the root pointer or in
values are:
Contains the physical base address (in bits 31-4) of the translation table
at the root pointer level. When the DT field contains $1, the value in the
offset).
other unused bits must always be zeros.
next level of table search (the function code level cannot be limited). To
Bits 3-0 of the root pointer are not used and are ignored when written. All
This value is not allowed at the root pointer level. When a root pointer
configuration exception is taken.
A translation table for this root pointer does not exist. The MC68030
this root pointer within the current page by adding (unsigned) the value
case, the processor performs a limit check, regardless of the state of
the FCL bit in the TC register.
The translation table at the root of the translation tree contains short-
format descriptors. The MC68030 must scale the table index for this
The translation table at the root of the translation tree contains long-
format descriptors. The MC68030 must scale the table index for this
register is loaded with an invalid root pointer descriptor, an MMU
PAGE DESCRIPTOR
internally calculates an ATC entry (page descriptor) for accesses using
in the table address field to the incoming logical address. This results
in direct mapping with a constant offset (the table address). For this
level of the table search by 4 bytes to access the next descriptor.
level of the table search by 8 bytes to access the next descriptor.
MC68030 USER'S MANUAL
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