4-7
PERIPHERAL CONTROL BLOCK
As an example, to relocate the Peripheral Control Block to the memory range 10000-100FFH, the
user would program the PCB Relocation Register with the value 1100H. Since the Relocation
Register is part of the Peripheral Control Block, it relocates to word 10000H plus its fixed offset.
NOTE
Due to an internal condition, external ready is ignored if the device is
configured in Cascade mode and the Peripheral Control Block (PCB) is
located at 0000H in I/O space. In this case, wait states cannot be added to
interrupt acknowledge bus cycles. However, you can add wait states to
interrupt acknowledge cycles if the PCB is located at any other address.
4.5.1
Considerations for the 80C187 Math Coprocessor Interface
Systems using the 80C187 math coprocessor interface must not relocate the Peripheral Control
Block to location 0000H in I/O space. The 80C187 interface uses I/O locations 0F8H through
0FFH. If the Peripheral Control Block resides in these locations, the processor communicates
with the Peripheral Control Block, not the 80C187 interface circuitry.
NOTE
If the PCB is located at 0000H in I/O space and access to the math coprocessor
interface is enabled (the Escape Trap bit is clear), a numerics (ESC) instruction
causes indeterminate system operation.
Since the 8-bit bus version of the device does not support the 80C187, it automatically traps an
ESC instruction to the Type 7 interrupt, regardless of the state of the Escape Trap (ET) bit.
For details on the math coprocessor interface, see Chapter 11, “Math Coprocessing.”
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: ......