Hitachi H8S/2645, Hardware Manual

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When TGR is an input capture register
When input capture occurs, the value in TCNT is transferred to TGR and the value previously
held in the timer general register is transferred to the buffer register.
This operation is illustrated in figure 10-17.
Buffer register
Timer general
register
TCNT
Input capture
signal
Figure 10-17 Input Capture Buffer Operation
Example of Buffer Operation Setting Procedure: Figure 10-18 shows an example of the buffer
operation setting procedure.
Select TGR function
Buffer operation
Set buffer operation
Start count
<Buffer operation>
[1]
[2]
[3]
[1] Designate TGR as an input capture register or
output compare register by means of TIOR.
[2] Designate TGR for buffer operation with bits
BFA and BFB in TMDR.
[3] Set the CST bit in TSTR to 1 to start the count
operation.
Figure 10-18 Example of Buffer Operation Setting Procedure