CHIP-SELECT UNIT
6-6
6.4 PROGRAMMING
Four registers determine the operating characteristics of the chip-selects. The Peripheral Control
Block defines the location of the Chip-Select Unit registers. Table 6-1 lists the registers and their
associated programming names.
The control registers (Figures 6-5 through 6-7) define the base address and bus ready and wait
state requirements for the corresponding chip-selects. The alternate control register (Figure 6-9)
defines the block size for MCS3:0. It also selects memory or I/O space for PCS6:0, selects the
function of the PCS6:5 pins, and defines the bus ready and wait state requirements for PCS6:4.
6.4.1 Initialization Sequence
Chip-selects do not have to be initialized in any specific order. However, the following guidelines
help prevent a system failure.
1. Initialize local memory chip-selects
2. Initialize local peripheral chip-selects
3. Perform local diagnostics
4. Initialize off-board memory and peripheral chip-selects
5. Complete system diagnostics
An unmasked interrupt or NMI must not occur until the interrupt vector addresses have been writ-
ten to memory. Failure to prevent an interrupt from occurring during initialization will cause a
system failure. Use external logic to generate the chip-select if interrupts cannot be masked prior
to initialization.
Table 6-1. Chip-Select Unit Registers
Control Register
Mnemonic
Alternate Register
Mnemonic
Chip-Select Affected
UMCS
None
UCS
LMCS
None
LCS
MMCS
MPCS
MCS3:0
PACS
MPCS
PCS6:0
Содержание 80C186EA
Страница 1: ...80C186EA 80C188EA Microprocessor User s Manual...
Страница 2: ...80C186EA 80C188EA Microprocessor User s Manual 1995...
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Страница 20: ...1 Introduction...
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Страница 28: ...2 Overview of the 80C186 Family Architecture...
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Страница 80: ...3 Bus Interface Unit...
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Страница 130: ...4 Peripheral Control Block...
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Страница 140: ...5 ClockGenerationand Power Management...
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Страница 166: ...6 Chip Select Unit...
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Страница 190: ...7 Refresh Control Unit...
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Страница 206: ...8 Interrupt Control Unit...
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Страница 239: ...INTERRUPT CONTROL UNIT 8 32...
Страница 240: ...9 Timer Counter Unit...
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Страница 266: ...10 Direct Memory Access Unit...
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Страница 295: ...DIRECT MEMORY ACCESS UNIT 10 28...
Страница 296: ...11 Math Coprocessing...
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Страница 314: ...12 ONCE Mode...
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Страница 318: ...A 80C186 Instruction Set Additions and Extensions...
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Страница 330: ...B Input Synchronization...
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Страница 334: ...C Instruction Set Descriptions...
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Страница 383: ...INSTRUCTION SET DESCRIPTIONS C 48...
Страница 384: ...D Instruction Set Opcodes and Clock Cycles...
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Страница 408: ...Index...
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