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Intel 386 User Manual

Page 7

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Intel386™ EX MICROPROCESSOR USER’S MANUAL

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7.3.4.2

SMRAM State Dump Area .................................................................................7-14

7.3.5

Resume Instruction (RSM) ......................................................................................7-15

7.4

THE Intel386 EX PROCESSOR IDENTIFIER REGISTERS ....................................... 7-15

7.5

PROGRAMMING CONSIDERATIONS........................................................................ 7-16

7.5.1

System Management Mode Code Example ............................................................7-16

CHAPTER 8

CLOCK AND POWER MANAGEMENT UNIT

8.1

OVERVIEW ................................................................................................................... 8-1

8.1.1

Clock Generation Logic .............................................................................................8-1

8.1.2

Power Management Logic ........................................................................................8-3

8.1.2.1

SMM Interaction with Power Management Modes ...............................................8-4

8.1.2.2

Bus Interface Unit Operation During Idle Mode ....................................................8-5

8.1.2.3

Watchdog Timer Unit Operation During Idle Mode ..............................................8-5

8.1.3

Clock and Power Management Registers and Signals .............................................8-6

8.2

CONTROLLING THE PSCLK FREQUENCY ................................................................ 8-7

8.3

CONTROLLING POWER MANAGEMENT MODES ..................................................... 8-8

8.3.1

Idle Mode ..................................................................................................................8-9

8.3.2

Powerdown Mode ...................................................................................................8-10

8.3.3

Ready Generation During HALT .............................................................................8-10

8.4

DESIGN CONSIDERATIONS...................................................................................... 8-11

8.4.1

Reset Considerations ..............................................................................................8-11

8.4.2

Power-up Considerations ........................................................................................8-12

8.4.2.1

Built-in Self Test .................................................................................................8-12

8.4.2.2

JTAG Reset ........................................................................................................8-12

8.4.3

Powerdown Mode and Idle Mode Considerations ...................................................8-13

8.5

PROGRAMMING CONSIDERATIONS........................................................................ 8-13

8.5.1

Clock and Power Management Unit Code Example ...............................................8-13

CHAPTER 9

INTERRUPT CONTROL UNIT

9.1

OVERVIEW ................................................................................................................... 9-1

9.2

ICU OPERATION........................................................................................................... 9-4

9.2.1

Interrupt Sources ......................................................................................................9-4

9.2.2

Interrupt Priority ........................................................................................................9-6

9.2.2.1

Assigning an Interrupt Level .................................................................................9-6

9.2.2.2

Determining Priority ..............................................................................................9-7

9.2.3

Interrupt Vectors .......................................................................................................9-8

9.2.4

Interrupt Process .......................................................................................................9-9

9.2.5

Poll Mode ................................................................................................................9-14

9.3

REGISTER DEFINITIONS........................................................................................... 9-15

9.3.1

Port 3 Configuration Register (P3CFG) ..................................................................9-18

9.3.2

Interrupt Configuration Register (INTCFG) .............................................................9-19