3-29
BUS INTERFACE UNIT
Figure 3-25. HALT Bus Cycle
Table 3-6. HALT Bus Cycle Pin States
Pin(s)
Pin State
AD15:0 (AD7:0 for 8-bit)
Float
A15:8 (8-bit)
Drive Address
A19:16
Drive 8H or Zero
BHE (16-bit)
Drive Last Value
RD, WR, DEN, DT/R, RFSH (8-bit), S2:0
Drive One
011
CLKOUT
ALE
S2:0
AD15:0
[AD7:0]
[A15:8]
A19:16
NOTES:
1. The AD15:0 [AD7:0] bus can be floating, driving a previous write data value,
or driving the next instruction prefetch address value. For an 8-bit device,
A15:8 drives either the previous bus address value or the next instruction
prefetch address value.
2. The A19:16 bus drives either zero (all low) or 8H (all low except A19/S6,
which can be high if the previous bus cycle was a DMA or refresh operation).
T1
TI
TI
BHE
[RFSH = 1]
Note 1
Note 1
Note 2
A1513-0A
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: ......