Motorola M68060 User Manual page 255

RW—Read and Write
00 = Undefined, reserved
01 = Write
10 = Read
11 = Read-Modify-Write
A read-modify-write indicates that the referenced address is capable of being read and
written. For example, for an ADD D0,<ea> instruction, the memory operand is read, mod-
ified, and then written by this instruction. A read-modify-write does not imply a "locked"
sequence.
SIZE—Transfer Size
00 = Byte
01 = Word
10 = Long
11 = Double Precision or MOVE16
The SIZE field corresponds to the original access size. If a data cache line read results
from a read miss and the line read encounters a bus error, the SIZE field in the resulting
stack frame indicates the size of the original read generated by the execution unit.
TT—Transfer Type
This field defines the TT1–TT0 signal encoding for the faulted access.
TM—Transfer Modifier
This field defines the TM2–TM0 signal encoding for the faulted access.
PBE—Push Buffer Bus Error
0 = Fault not caused by a bus error (TEA asserted) during a push buffer write.
1 = Fault caused by a bus error (TEA asserted) during a push buffer write.
SBE—Store Buffer Bus Error
0 =Fault not caused by a bus error (TEA asserted) during a store buffer write.
1 =Fault caused by a bus error (TEA asserted) during a store buffer write.
PTA—Pointer A Fault
0 =Fault not due to an invalid root level descriptor.
1 =Fault due to an invalid root level descriptor.
PTB—Pointer B Fault
0 =Fault not due to an invalid pointer level descriptor.
1 =Fault due to an invalid pointer level descriptor.
IL—Indirect Level Fault
0 =Fault not due to encountering a second indirect page descriptor.
1 =Fault due to encountering a second indirect page descriptor.
MOTOROLA M68060 USER'S MANUAL
Exception Processing
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