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MPC8260 PowerQUICC II UserÕs Manual
MOTOROLA
Part II. ConÞguration and Reset
The SIVEC can be read as either a byte, half word, or a word. When read as a byte, a branch
table can be used in which each entry contains one instruction (branch). When read as a half
word, each entry can contain a full routine of up to 256 instructions. The interrupt code is
deÞned such that its two lsbs are zeroes, allowing indexing into the table, as shown in
Figure 4-19.
Figure 4-19. Interrupt Table Handling Example
Note that the MPC8260 differs from previous MPC8xx implementations in that when an
interrupt request occurs, SIVEC can be read. If there are multiple interrupt sources, SIVEC
latches the highest priority interrupt. Note that the value of SIVEC cannot change while it
is being read.
4.3.1.7 SIU External Interrupt Control Register (SIEXR)
Each deÞned bit in the SIU external interrupt control register (SIEXR), shown in
Figure 4-20, determines whether the corresponding port C line asserts an interrupt request
upon either a high-to-low change or any change on the pin. External interrupts can come
from port C (PC[0-15]).
BASE
b Routine1
b Routine2
b Routine3
b Routine4
•
•
BASE + n
BASE + 4
BASE + 8
BASE + C
BASE +10
BASE
1st Instruction of Routine1
1st Instruction of Routine2
1st Instruction of Routine3
1st Instruction of Routine4
•
•
BASE + n
BASE + 400
BASE + 800
BASE + C00
BASE +1000
•
•
•
•
•
•
INTR: ¥ ¥ ¥
Save state
R3 <- @ SIVEC
R4 <-- Base of branch table
¥ ¥ ¥
lbz
add
mtspr
bctr
RX, R3 (0)
# load as byte
RX, RX, R4
CTR, RX
INTR: ¥ ¥ ¥
Save state
R3 <- @ SIVEC
R4 <-- Base of branch table
¥ ¥ ¥
lhz
add
mtspr
bctr
RX, R3 (0)
# load as half
RX, RX, R4
CTR, RX
Summary of Contents for MPC8260 PowerQUICC II
Page 1: ...MPC8260UM D 4 1999 Rev 0 MPC8260 PowerQUICC II UserÕs Manual ª ª ...
Page 66: ...lxvi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA ...
Page 88: ...1 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 120: ...2 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part I Overview ...
Page 138: ...Part II iv MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II Configuration and Reset ...
Page 184: ...4 46 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part II ConÞguration and Reset ...
Page 202: ...Part III vi MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 266: ...8 34 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 382: ...10 106 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 392: ...11 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part III The Hardware Interface ...
Page 430: ...Part IV viii MOTOROLA Part IV Communications Processor Module ...
Page 490: ...14 36 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 524: ...17 10 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 556: ...18 32 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 584: ...19 28 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
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Page 652: ...22 20 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
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Page 920: ...31 18 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Part IV Communications Processor Module ...
Page 980: ...A 4 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA Appendixes ...
Page 1002: ...Index 22 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA INDEX ...
Page 1006: ......