Renesas SH7041 Series, Hardware Manual, Page: 380 / 923

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The TSR register TCFD bit is a count direction flag. Read the TCFD flag to confirm whether the
TCNT is incrementing or decrementing.
Table 12.8 shows the correspondence between channels and external clock pins.
Table 12.8 Phase Counting Mode Clock Input Pins
Channel A Phase Input Pin B Phase Input Pin
1 TCLKA TCLKB
2 TCLKC TCLKD
Procedure for Selecting the Phase Counting Mode (Figure 12.29):
1.Set the MD3–MD0 bits of the timer mode register (TMDR) to select the phase counting mode.
2.Set the CST bit of the timer start register (TSTR) to 1 to start the count.
Phase counting mode
Select phase counting mode
Start counting
Phase counting mode
1
2
Figure 12.29 Procedure for Selecting the Phase Counting Mode
Phase Counting Operation Examples: The phase counting mode uses the phase difference
between two external clocks to increment/decrement the TCNT counter. There are 4 modes,
depending on the count conditions.
Phase Counting Mode 1: Figure 12.30 shows an example of phase counting mode 1 operation.
Table 12.9 lists the up counting and down counting conditions for the TCNT.