INTERRUPT CONTROL UNIT
8-22
Figure 8-13. End-of-Interrupt Register
8.4.8 Interrupt Status Register
The Interrupt Status register (Figure 8-14) contains the DMA Halt bit and one bit for each timer
interrupt. The CPU sets the DMA Halt bit to suspend DMA transfers while an NMI is processed.
Software can also read and write this bit. See “Suspension of DMA Transfers” on page 10-20 for
details. A timer bit is set to indicate a pending interrupt and is cleared when the interrupt request
is acknowledged. Any number of bits can be set at any one time.
Register Name:
End-of-Interrupt Register
Register Mnemonic:
EOI
Register Function:
Used to issue an EOI command
Bit
Mnemonic
Bit Name
Reset
State
Function
NSPEC
Nonspecific
EOI
0
Set to issue a nonspecific EOI.
VT4:0
Interrupt
Type
0 0000
Write with the interrupt type of the interrupt
whose In-Service bit is to be cleared.
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.
A1210-A0
15
0
V
T
0
V
T
2
V
T
3
V
T
4
N
S
P
E
C
V
T
1
Содержание 80C186EA
Страница 1: ...80C186EA 80C188EA Microprocessor User s Manual...
Страница 2: ...80C186EA 80C188EA Microprocessor User s Manual 1995...
Страница 19: ......
Страница 20: ...1 Introduction...
Страница 21: ......
Страница 28: ...2 Overview of the 80C186 Family Architecture...
Страница 29: ......
Страница 79: ......
Страница 80: ...3 Bus Interface Unit...
Страница 81: ......
Страница 129: ......
Страница 130: ...4 Peripheral Control Block...
Страница 131: ......
Страница 139: ......
Страница 140: ...5 ClockGenerationand Power Management...
Страница 141: ......
Страница 165: ......
Страница 166: ...6 Chip Select Unit...
Страница 167: ......
Страница 190: ...7 Refresh Control Unit...
Страница 191: ......
Страница 205: ......
Страница 206: ...8 Interrupt Control Unit...
Страница 207: ......
Страница 239: ...INTERRUPT CONTROL UNIT 8 32...
Страница 240: ...9 Timer Counter Unit...
Страница 241: ......
Страница 265: ......
Страница 266: ...10 Direct Memory Access Unit...
Страница 267: ......
Страница 295: ...DIRECT MEMORY ACCESS UNIT 10 28...
Страница 296: ...11 Math Coprocessing...
Страница 297: ......
Страница 314: ...12 ONCE Mode...
Страница 315: ......
Страница 318: ...A 80C186 Instruction Set Additions and Extensions...
Страница 319: ......
Страница 330: ...B Input Synchronization...
Страница 331: ......
Страница 334: ...C Instruction Set Descriptions...
Страница 335: ......
Страница 383: ...INSTRUCTION SET DESCRIPTIONS C 48...
Страница 384: ...D Instruction Set Opcodes and Clock Cycles...
Страница 385: ......
Страница 408: ...Index...
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