DS89C420-QCL Datasheet, PDF (3/139 Pages) Maxim Integrated Products – Ultra-High-Speed Flash Microcontroller User’s Guide

Ultra-High-Speed Flash
Microcontroller User’s Guide
SECTION 7: POWER MANAGEMENT
79
Power Management Summary
80
Precision Voltage Monitor
81
Early-Warning Power-Fail Interrupt
81
Power-Fail Reset
81
Power-On Reset
82
Bandgap Select
82
Watchdog Wake-Up from Idle
82
Power Saving
82
Clock Divide Control
82
Idle Mode
83
Stop Mode
84
Ring Oscillator Wake-Up from Stop
84
Speed Reduction
85
Power Management Modes
85
Switchback
87
Clock Source Selection
88
Ring Oscillator Resume from Stop
89
SECTION 8: RESET CONDITIONS
89
Reset Sources
89
Power-On/Power-Fail Reset
89
Watchdog Timer Reset
90
Oscillator Fail-Detect Reset
90
Determining the Cause of a Reset
90
SECTION 9: INTERRUPTS
91
Interrupt Overview
91
Interrupt Sources
92
Interrupt Priorities
93
Interrupt Acknowledge Cycle
94
Interrupt Latency
95
SECTION 10: I/O PORTS
95
Parallel I/O
96
Port 0
96
Port 2
97
Port 1
97
Port 3
97
Alternate Functions of Ports 1 and 3
97
Read-Modify-Write
99
Output Functions
99
Input Functions
100
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