SN8P2200 Series
USB 1.1 Low-Speed 8-Bit Micro-Controller
SONiX TECHNOLOGY CO., LTD
Page 93
Version 1.7
8.5.5 Tn INPUT PERIOD MEASUREMENT
Tn edge trigger as falling edge and rising edge is period measurement function. Input period measurement is equal to
input frequency measure. The period is the frequency inverse. Falling to falling of signal includes one high pulse and
one low pulse. The combination of high and low pulses is a full cycle signal. Rising to rising edge is the same. Set Tn
time base and select Tn edge as falling edge or rising edge, the Tn function is to measure input signal’s period
(frequency).
z
Falling edge trigger period measurement waveform.
Tn Input Signal
Tn Timer Counter
Falling edge trigger.
Tn start to count.
TnIRQ=0
Falling edge trigger.
Tn stop counting.
TnIRQ=1.
z
Rising edge trigger period measurement waveform.
Tn Input Signal
Tn Timer Counter
Rising edge trigger.
Tn start to count.
TnIRQ=0
Rising edge trigger.
Tn stop counting.
TnIRQ=1.