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A - SIMPLE 8-BIT TIMER   D - 8-BIT PWM
 MICROPROCESSOR{  -1  ~   ,E,,,   UP COUNiER   8-611 UPlOOWN   FLIP-FLOP   h PWM  OUTPUT
 tp
                                        &BIT LATCH
 DATA   ROLLOVER   OUTPUT    MA ,H
 BUS                                 U       I
                     I                          -  MICROPROCESSOR
                                                -
                                                     DATA
 DECODED WRITE STROBE  l-                            BUS
                                     HA
                                             I
 MICROPROCESSOR                                   DECODE0 WRITE STROBE
 CLOCK OR EXTERNAL   CLOCK     COMPARATOR
 CLOCK
 B - RELOADING 8-BIT TIMER
 EBlT LATCH   8-BIT UP COUNTER
 MICROPROCESSOR
 DATA   0-
 BUS
 -39  II
 DECODED WRITE STROBE
 MICROPROCESSOR
 CLOCK  OR EXTERNAL
 CLOCK






  MICROPROCESSOR
     DATA
 5'
 +   CLR
 MICROPROCESSOR
 CLOCK OR EXTERNAL
 CLOCK
 c


 k
 Figure 3.5
 Timers.
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