User’s Manual
Preliminary
PPC440x5 CPU Core
prgmodel.fm.
September 12, 2002
Page 67 of 589
When being used as a return address by a bclr instruction, bits 30:31 of the LR are ignored, since all instruc-
tion addresses are on word boundaries.
Access to the LR is non-privileged.
2.5.5.2 Count Register (CTR)
The CTR is written from a GPR using
mtspr, and can be read into a GPR using mfspr. The CTR contents
can be used as a loop count that gets decremented and tested by conditional branch instructions that specify
count decrement as one of their branch conditions (instruction field BO[2] = 0). Alternatively, the CTR
contents can specify a target address for the
bcctr instruction, enabling indirect branching to any address.
Access to the CTR is non-privileged.
2.5.5.3 Condition Register (CR)
The CR is used to record certain information (“conditions”) related to the results of the various instructions
which are enabled to update the CR. A bit in the CR may also be selected to be tested as part of the condition
of a conditional branch instruction.
The CR is organized into eight 4-bit fields (CR0–CR7), as shown in Figure 2-5. Table 2-24 lists the instruc-
tions which update the CR.
Access to the CR is non-privileged.
Figure 2-3. Link Register (LR)
0:31
Link Register contents
Target address of bclr instruction
Figure 2-4. Count Register (CTR)
0:31
Count
Used as count for branch conditional with decre-
ment instructions, or as target address for bcctr
instructions
0
31
0
31
Содержание PPC440X5 CPU Core
Страница 1: ...PPC440x5 CPU Core User s Manual Preliminary SA14 2613 02 September 12 2002 Title Page...
Страница 22: ...User s Manual PPC440x5 CPU Core Preliminary Page 22 of 583 ppc440x5LOT fm September 12 2002...
Страница 26: ...User s Manual PPC440x5 CPU Core Preliminary Page 26 of 589 preface fm September 12 2002...
Страница 38: ...User s Manual PPC440x5 CPU Core Preliminary Page 38 of 589 overview fm September 12 2002...
Страница 94: ...User s Manual PPC440x5 CPU Core Preliminary Page 94 of 589 init fm September 12 2002...
Страница 132: ...User s Manual PPC440x5 CPU Core Preliminary Page 132 of 589 cache fm September 12 2002...
Страница 158: ...User s Manual PPC440x5 CPU Core Preliminary Page 158 of 589 mmu fm September 12 2002...
Страница 218: ...User s Manual PPC440x5 CPU Core Preliminary Page 218 of 589 timers fm September 12 2002...
Страница 248: ...User s Manual PPC440x5 CPU Core Preliminary Page 248 of 589 debug fm September 12 2002...
Страница 458: ...User s Manual PPC440x5 CPU Core Preliminary Page 458 of 589 regsummIntro fm September 12 2002...
Страница 568: ...User s Manual PPC440x5 CPU Core Preliminary Page 568 of 589 instalfa fm September 12 2002...
Страница 588: ...User s Manual PPC440x5 CPU Core Preliminary Page 588 of 583 ppc440x5IX fm September 12 2002...
Страница 590: ......