6-11
CHIP-SELECT UNIT
Figure 6-9. MPCS Register Definition
Register Name:
MCS and PCS Alternate Control Register
Register Mnemonic:
MPCS
Register Function:
Controls operation of the MCS and PCS chip-
selects.
Bit
Mnemonic
Bit Name
Reset
State
Function
M6:0
Block Size
XXH
Defines the block size for the MCS chip-selects.
Table 6-5 on page 6-14 lists allowable values.
EX
Pin Selector
XH
Setting EX configures PCS6:5 as chip-selects.
Clearing EX configures the pins as latched
address bits A2:A1.
MS
Bus Cycle
Selector
XH
Clearing MS activates PCS6:0 for I/O bus
cycles. Setting MS activates PCS6:0 for
memory bus cycles.
R2
Bus Ready
Disable for
PCS6:4
X
Applies only to PCS6:4. When R2 is clear, bus
ready must be active to complete a bus cycle.
When R2 is set, R1:0 control the number of bus
wait states and bus ready is ignored.
R1:0
Wait State
Value for
PCS6:4
3H
Apply only to PCS6:4. R1:0 define the minimum
number of wait states inserted into the bus
cycle.
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. A starting address
other than an integer multiple of the block size defined in this register causes
unreliable chip-select operation. Reading this register and the MMCS or PACS
register (before writing them) enables the associated chip-selects; however, none
of the programmable fields will be properly initialized.
15
0
R
1
R
0
R
2
E
X
M
S
M
1
M
0
M
3
M
2
M
5
M
4
M
6
A1144-0A
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: ......