
MOTOROLA
Chapter 2. Programming Model
2-45
2.3.6.3.2 Segment Register Manipulation Instructions
The instructions listed in Table 2-41 provide access to the segment registers for the 603e.
These instructions operate completely independently of the MSR[IR] and MSR[DR] bit
settings. Refer to “Synchronization Requirements for Special Registers and TLBs” in
Chapter 2, “Register Set,” in
The Programming Environments Manual
for serialization
requirements and other recommended precautions to observe when manipulating the
segment registers.
2.3.6.3.3 Translation Lookaside Buffer Management Instructions
The address translation mechanism is defined in terms of segment descriptors and page
table entries (PTEs) used by PowerPC processors to locate the effective-to-physical address
mapping for a particular access. The PTEs reside in page tables in memory. As defined for
32-bit implementations by the PowerPC architecture, segment descriptors reside in 16 on-
chip segment registers.
Implementation Note
—The 603e provides the ability to invalidate a TLB entry. The TLB
Invalidate Entry (
tlbie
) instruction invalidates the TLB entry indexed by the EA, and
operates on both the instruction and data TLBs simultaneously invalidating four TLB
entries (both sets in each TLB). The index corresponds to bits 15–19 of the EA. To
invalidate all entries within both TLBs, 32
tlbie
instructions should be issued, incrementing
this field by one each time.
The 603e provides two implementation-specific instructions (
tlbld
and
tlbli
) that are used
by software table search operations following TLB misses to load TLB entries on-chip.
For more information on
tlbld
and
tlbli
refer to Section 2.3.8, “Implementation-Specific
Instructions.”
Note that the
tlbia
instruction is not implemented on the 603e.
Table 2-41. Segment Register Manipulation Instructions
Name
Mnemonic
Operand Syntax
Move to Segment Register
mtsr
SR
,r
S
Move to Segment Register Indirect
mtsrin
r
S
,r
B
Move from Segment Register
mfsr
r
D
,
SR
Move from Segment Register Indirect
mfsrin
r
D
,r
B