8-15
INTERRUPT CONTROL UNIT
Figure 8-6. Interrupt Control Register for Cascadable Interrupt Pins
Register Name:
Interrupt Control Register (cascadable pins)
Register Mnemonic:
I0CON, I1CON
Register Function:
Control register for the cascadable external
interrupt pins
Bit
Mnemonic
Bit Name
Reset
State
Function
SFNM
Special
Fully
Nested
Mode
0
Set to enable special fully nested mode.
CAS
Cascade
Mode
0
Set to enable cascade mode.
LVL
Level-trigger
0
Selects the interrupt triggering mode:
0 = edge triggering
1 = level triggering.
The LVL bit
must be set
when external 8259As
are cascaded into the Interrupt Control Unit.
MSK
Interrupt
Mask
1
Clear to enable interrupts from this source.
PM2:0
Priority
Level
111
Defines the priority level for this source.
NOTE:
Reserved register bits are shown with gray shading. Reserved bits must be written
to a logic zero to ensure compatibility with future Intel products.
A1215-A0
15
0
P
M
0
P
M
1
P
M
2
M
S
K
L
V
L
C
A
S
S
F
N
M
Содержание 80C186XL
Страница 1: ...80C186XL 80C188XL Microprocessor User s Manual...
Страница 2: ...80C186XL 80C188XL Microprocessor User s Manual 1995...
Страница 18: ...1 Introduction...
Страница 19: ......
Страница 27: ......
Страница 28: ...2 Overview of the 80C186 Family Architecture...
Страница 29: ......
Страница 79: ......
Страница 80: ...3 Bus Interface Unit...
Страница 81: ......
Страница 127: ......
Страница 128: ...4 Peripheral Control Block...
Страница 129: ......
Страница 137: ......
Страница 138: ...5 ClockGenerationand Power Management...
Страница 139: ......
Страница 154: ...6 Chip Select Unit...
Страница 155: ......
Страница 178: ...7 Refresh Control Unit...
Страница 179: ......
Страница 193: ......
Страница 194: ...8 Interrupt Control Unit...
Страница 195: ......
Страница 227: ......
Страница 228: ...9 Timer Counter Unit...
Страница 229: ......
Страница 253: ......
Страница 254: ...10 Direct Memory Access Unit...
Страница 255: ......
Страница 283: ......
Страница 284: ...11 Math Coprocessing...
Страница 285: ......
Страница 302: ...12 ONCE Mode...
Страница 303: ......
Страница 306: ...A 80C186 Instruction Set Additions and Extensions...
Страница 307: ......
Страница 318: ...B Input Synchronization...
Страница 319: ......
Страница 322: ...C Instruction Set Descriptions...
Страница 323: ......
Страница 371: ......
Страница 372: ...D Instruction Set Opcodes and Clock Cycles...
Страница 373: ......
Страница 396: ...Index...
Страница 397: ......