Chapter 10. Memory Management Unit (MMU)
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10-15
MMU Definition
10.5.3.6 MMU Fault, Test, or TLB Address Register (MMUAR)
The MMUAR format, Figure 10-7, depends on how the register is used.
Table 10-8 describes MMUAR fields.
10.5.3.7 MMU Read/Write Tag and Data Entry Registers
(MMUTR and MMUDR)
Each TLB entry consists of a 32-bit TLB tag entry and a 32-bit TLB data entry. TLB entries
are referenced through MMUTR and MMUDR. For read TLB accesses, the contents of the
TLB tag and data entries referenced by the allocation address or MMUAR are loaded in
Table 10-7. MMUSR Field Descriptions
Bits
Name
Description
31–6
—
Reserved, should be cleared. Writes are ignored and reads return zeros.
5
SPF
Supervisor protect fault. Indicates if the last data fault was a user mode access that hit in a TLB entry
that had its supervisor protect bit set.
0 Last data access fault did not have a supervisor protect fault.
1 Last data access fault had a supervisor protect fault.
4
RF
Read access fault. Indicates if the last data fault was an data read access that hit in a TLB entry that
did not have its read bit set.
0 Last data access fault did not have a read protect fault.
1 Last data access fault had a read protect fault.
3
WF
Write access fault. Indicates if the last data fault was an data write access that hit in a TLB entry that
did not have its write bit set.
0 Last data access fault did not have a write protect fault.
1 Last data access fault had a write protect fault.
2
—
Reserved, should be cleared. Writes are ignored and reads return zeros.
1
HIT
Search TLB hit. Indicates if the last data fault or the last search TLB operation hit in the TLB.
0 Last data access fault or search TLB operation did not hit in the TLB.
1 Last data access fault or search TLB operation hit in the TLB.
0
—
Reserved, should be cleared. Writes are ignored and reads return zeros.
31
0
Field
FA
Reset
—
R/W
R/W
Rc
0x0010
Figure 10-7. MMU Fault, Test, or TLB Register (MMUAR)
Table 10-8. MMUAR Field Descriptions
Bits
Name
Description
31–0
FA
Form address. Written by the MMU with the virtual address on DTLB misses and access faults. For
this case, all 32 bits are address bits. This register may be written with a virtual address and address
attribute information for searching the TLB (MMUCR[STLB]). For this case, FA[31–1] are the virtual
page number and FA[0] is the supervisor bit. The current ASID is used for the TLB search. MMUAR
can also be written with a TLB address for use with the access TLB function (using MMUCR[ACC]).
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