3-35
BUS INTERFACE UNIT
Figure 3-30. Exiting HALT (Active/Idle Mode)
3.6
SYSTEM DESIGN ALTERNATIVES
Most system designs require no signals other than those already provided by the BIU. However,
heavily loaded bus conditions, slow memory or peripheral device performance and off-board de-
vice interfaces may not be supported directly without modifying the BIU interface. The following
sections deal with topics to enhance or modify the operation of the BIU.
CLKOUT
AD15:0
[AD7:0]
ALE
[A15:8]
A19:16
Note 3
NOTES:
1. For NMI, delay = 4 1/2 clocks. For INTx, delay = 7 1/2 clocks (min).
2. If previous bus cycle was a read, bus will float. If previous bus cycle was
a write, bus will drive data value.
3. Previous bus cycle value.
4. If previous bus cycle was a refresh or DMA bus cycle, value will be
8H (A19 = 1); otherwise, value will be 0.
S2:0
BHE
RFSH
Note 4
NMI/INTx
Address
Note 3
Addr
Note 2
Note 1
Valid
A1055-0A
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...
Страница 409: ......