MC68030RC20C Freescale Semiconductor, MC68030RC20C Datasheet - Page 324

• Manufacturer Part Number: MC68030RC20C
• Description: IC MPU 32BIT ENHANCED 128-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68030RC20C

• Processor Type: M680x0 32-Bit
• Speed: 20MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 128-PGA
• Family Name: M68000
• Device Core: ColdFire
• Device Core Size: 32b
• Frequency (max): 20MHz
• 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

9,5.1.2 ROOT POINTER DESCRIPTOR. A root pointer descriptor contains the ad-
MOTOROLA
field descriptions in the preceding section apply to corresponding fields of
the CRP and SRP with two minor exceptions. A descriptor-type code of $00
DESCRIPTOR ADDRESS
RESERVED
dress of the top-level pointer table of a translation tree. This type of descriptor
is loaded into the CRP and SRP registers with the PMOVE instruction. The
or SRP register results in an MMU configuration exception. Also, when the
UNUSED
(invalid) is not allowed; an attempt to load zero into the DT field of the CRP
FCL field of the TC register is set, the L/U and LIMIT fields of the root pointer
registers are unused. Figure 9-9 shows the root pointer descriptor format.
This 30-bit field; which contains the physical address of a page descriptor,
The bits in this field are not used by the MC68030 and may be used by the
for future definition. These bits should be consistently written as either a
for any purpose may not be supported in future products.
is only used in short- and long-format indirect descriptors.
system software.
Descriptor fields designated by a one or a zero are reserved by Motorola
one or a zero as appropriate. In the root pointers, these bits are not alterable.
In memory-resident descriptors, the values in these fields are neither
checked nor altered by the MC68030. Use of these bits by system software
L/U
63
15
0
L/U - - LowER OR UPPER PAGE RANGE
TABLE ADDRESS - - ADDRESS OF'TABLE AT NEXT LEVEL OR P~GE OFFSET IF DT= 1
OT - - DESCRIPTOR TYPE
LIMIT - - LIMIT ON TABLE INDEX FOR THIS TABLE ADDRESS
Figure 9-9. Root Pointer Descriptor Format
ol01oiolo
MC68030 USER'S MANUAL
TABLE ADDRESS (PA]5-PA4)
TABLE
o
ADDRESS IPA3;-P~ ~B
o
LIMIT
o
o
o oi o
~'
UNUSED
ol
48
0
9-23
9