MOTOROLA
Chapter 10. Instruction Execution Timing
10-3
Part II. PowerPC Microprocessor Module
10.1.3 Private Writeback Bus Load
In Figure 10-4, lwz and xor write back in the same clock since they use the writeback bus
in two different ticks (a tick = 1/4 of a processor clock).
lwz r12,64
(SP)
sub
r5,r5,3
cror
4,14,1
and
r3,r4.r5
xor
r4,r3,r5
ori
r6,r12.r3
Figure 10-4. Private Writeback Bus Load Timing
10.1.4 Fastest External Load (Data Cache Miss)
Figure 10-5 shows a sub instruction dependent on the value read by the load. It causes three
bubbles in the execution stream. Assuming SCCR[EBDF] = 00, the external clock
(CLKOUT) is shifted 90
°
from the internal clock (GCLK1).
lwz
r12,64 (SP)
sub
r3,r12,3
addic
r4,r14,1
Figure 10-5. External Load Timing
ori
xor
load
lwz
sub
and
xor
cror
ori
sub
and
cror
ori
load
sub
lwz
lwz
lwz
lwz
sub
lwz
cror
and
and
xor
xor
ori
GCLK1
E Data
Fetch
Decode
Read + Execute
Writeback
L Address Drive
L Data
Cache Address
Load Writeback
E Address
cror
lwz
sub
lwz
lwz
sub
addic
sub
sub
lwz
Bubble
lwz
lwz
lwz
lwz
lwz
lwz
GCLK1
E Data
Fetch
Decode
Read + Execute
Writeback
L Address Drive
L Data
Cache Address
Load Writeback
E Address
Bubble
Bubble
Bubble
Summary of Contents for MPC860 PowerQUICC
Page 3: ...MPC860UM AD 07 98 REV 1 MPC860 PowerQUICC ª UserÕs Manual ...
Page 36: ...xxxvi MPC860 PowerQUICC UserÕs Manual MOTOROLA CONTENTS Paragraph Number Title Page Number ...
Page 78: ...I iv MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Page 88: ...1 10 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Page 114: ...3 16 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part I Overview ...
Page 226: ...8 32 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part II PowerPC Microprocessor Module ...
Page 262: ...9 36 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part II PowerPC Microprocessor Module ...
Page 274: ...III iv MPC860 PowerQUICC UserÕs Manual MOTOROLA Part III Configuration ...
Page 320: ...12 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part III Configuration ...
Page 325: ...MOTOROLA Part IV Hardware Interface IV v Part IV Hardware Interface ...
Page 326: ...IV vi MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Page 352: ...13 26 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Page 394: ...14 42 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Page 426: ...15 32 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Page 530: ...17 26 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part IV Hardware Interface ...
Page 632: ...21 44 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 660: ...22 28 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 708: ...24 24 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 748: ...27 20 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 846: ...31 20 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 914: ...35 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 948: ...36 34 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part V The Communications Processor Module ...
Page 998: ...37 48 MPC860 PowerQUICC UserÕs Manual MOTOROLA Part VI Debug and Test ...
Page 1016: ...A 10 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Page 1024: ...B 8 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Page 1030: ...C 6 MPC860 PowerQUICC UserÕs Manual MOTOROLA Appendixes ...
Page 1086: ...Glossary 12 MPC860 PowerQUICC UserÕs Manual MOTOROLA ...
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