2002/4/8
2002/4/8
Microcomputers and Microprocessors
Microcomputers and Microprocessors
NATIONAL TAIWAN
NATIONAL TAIWAN
OCEAN UNIVERSITY
OCEAN UNIVERSITY
國國國國國國國國
國國國國國國國國
Chapter 9
Chapter 9
COUNTER/TIMER
COUNTER/TIMER
PROGRAMMING IN THE 8051
PROGRAMMING IN THE 8051

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2002 MuDer Jeng
2002 MuDer Jeng
Outlines
Outlines
♦
List the timers of the 8051 and their associated
List the timers of the 8051 and their associated
registers
registers
♦
Describe the various modes of the 8051 timers
Describe the various modes of the 8051 timers

2002 MuDer Jeng
TMOD (timer mode) register
TMOD (timer mode) register

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2002 MuDer Jeng
2002 MuDer Jeng

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2002 MuDer Jeng
2002 MuDer Jeng

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2002 MuDer Jeng
2002 MuDer Jeng

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2002 MuDer Jeng
2002 MuDer Jeng
Mode 1 programming
Mode 1 programming
1.Loaded value into TL and TH
2.”SETB TR0” for timer 0 ;”SETB TR1” for timer 1
3.If TF (timer flag) = high “CLR TR0” or “CLR TR1”
4.Reloaded TH and TL value, TF reset to 0



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2002 MuDer Jeng
2002 MuDer Jeng

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2002 MuDer Jeng
2002 MuDer Jeng