Input Capture - Fujitsu MB90390 Series Hardware Manual

13.5

Input Capture

Input capture detects a rising or falling edge or both edges of an external input signal
and stores a 16-bit free-run timer value at that time in a register. In addition, input
capture can generate an interrupt upon detection of an edge. Input capture consists of
an input capture data register and a control register.
■ Input Capture
Each input capture has a corresponding external input pin.
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The valid edge of an external input can be selected from the following three types:
Table 13.5-1 Types of External Input Edges
Rising edge
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An interrupt can be generated upon detection of a valid edge of an external input.
■ Input Capture Block Diagram
Figure 13.5-1 shows the input capture block diagram.
Bus
Note: The figure above is also valid for Input Capture Unit 2/3 and 4/5
Falling edge
Both edges
Figure 13.5-1 Input Capture Block Diagram
Capture data register 0
Count value from Free-run Timer
Capture data register 1
Edge detection
EG11 EG10 EG01 EG00
Edge detection
ICP1 ICP0 ICE1 ICE0
CHAPTER 13 16-BIT I/O TIMER
IN0
IEI1 IEI0
IN1
Interrupt
Interrupt
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