MC68EC040RC20A Freescale Semiconductor, MC68EC040RC20A Datasheet - Page 71

• Manufacturer Part Number: MC68EC040RC20A
• Description: IC MPU 32BIT 20MHZ 179-PGA
• Manufacturer: Freescale Semiconductor

Specifications of MC68EC040RC20A

• Processor Type: M680x0 32-Bit
• Speed: 20MHz
• Voltage: 5V
• Mounting Type: Surface Mount
• Package / Case: 179-PGA
• Lead Free Status / RoHS Status: Contains lead / RoHS Compliant
• Features: -

An alternate address space access is a special case that is immediately used as a
physical address without translation. Because the M68040 implements a merged
instruction and data space, the integer unit translates MOVES accesses to instruction
address spaces (SFC/DFC = $6 or $2) into data references (SFC/DFC = $5 or $1). The
data memory unit handles these translated accesses as normal data accesses. If the
access fails due to an ATC fault or a physical bus error, the resulting access error stack
frame contains the converted function code in the TM field for the faulted access.
Invalidation of the instruction cache line containing the referenced location to maintain
cache coherency must precede MOVES accesses that write the instruction address
space. The SFC and DFC values and results are listed in Table 3-2.
3-22
NOTE: WP indicates the accumulated write-protect status.
Previous Status
U-Bit
0
0
1
1
0
0
1
1
0
0
1
1
Table 3-1. Updating U-Bit and M-Bit for Page Descriptors
M-Bit
0
1
0
1
0
1
0
1
0
1
0
1
SFC/DFC Value
WP Bit
Freescale Semiconductor, Inc.
X
0
1
For More Information On This Product,
Table 3-2. SFC and DFC Values
000
001
010
011
100
101
110
111
Access
Read
Type
Write
M68040 USER'S MANUAL
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Locked RMW Access to Set U
Locked RMW Access to Set U
None
None
Write to Set U and M
Locked RMW Access to Set U
Write to Set M
None
Locked RMW Access to Set U
Locked RMW Access to Set U
None
None
TT
10
00
00
10
10
00
00
10
Update Operation
Page Descriptor
Results
000
001
001
011
100
101
101
111
TM
U-Bit
New Status
1
1
1
1
1
1
1
1
1
1
1
1
M-Bit
0
1
1
1
1
0
1
0
1
1
0
1
MOTOROLA