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7540 Group User’s Manual
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Table of contents
CHAPTER 1 HARDWARE
DESCRIPTION ................................................................................................................................ 1-2
FEATURES ...................................................................................................................................... 1-2
APPLICATION ................................................................................................................................ 1-2
PIN CONFIGURATION .................................................................................................................. 1-3
FUNCTIONAL BLOCK .................................................................................................................. 1-5
PIN DESCRIPTION ........................................................................................................................ 1-8
GROUP EXPANSION .................................................................................................................... 1-9
FUNCTIONAL DESCRIPTION .................................................................................................... 1-11
I/O Ports .................................................................................................................................. 1-17
Interrupts ................................................................................................................................. 1-21
Timers ...................................................................................................................................... 1-24
Serial I/O ................................................................................................................................. 1-35
Watchdog Timer ..................................................................................................................... 1-42
Reset Circuit ........................................................................................................................... 1-43
Clock Generating Circuit ....................................................................................................... 1-45
NOTES ON PROGRAMMING ..................................................................................................... 1-49
Processor Status Register .................................................................................................... 1-49
Interrupts ................................................................................................................................. 1-49
Decimal Calculations .............................................................................................................. 1-49
Ports ......................................................................................................................................... 1-49
A-D Conversion ...................................................................................................................... 1-49
CPU Mode Register ............................................................................................................... 1-49
State Transition ...................................................................................................................... 1-49
NOTES ON HARDWARE ............................................................................................................ 1-49
One Time PROM Version ..................................................................................................... 1-49
s Interrupt ............................................................................................................................... 1-50
s Timers .................................................................................................................................. 1-50
s Timer A ............................................................................................................................... 1-50
s Timer X ............................................................................................................................... 1-50
s Serial I/O ............................................................................................................................. 1-51
s A-D Converter .................................................................................................................... 1-51
ROM PROGRAMMING METHOD .............................................................................................. 1-53
Interrupt ................................................................................................................................... 1-54
Timing After Interrupt ............................................................................................................. 1-55