r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 763

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

11.4.6
In phase counting mode, the phase difference between two external clock inputs is detected and
TCNT is incremented/decremented accordingly. This mode can be set for channels 1, 2, 4, 5, 7, 8,
10, and 11.
When phase counting mode is set, an external clock is selected as the counter input clock and
TCNT operates as an up/down-counter regardless of the setting of bits TPSC2 to TPSC0 and bits
CKEG1 and CKEG0 in TCR. However, the functions of bits CCLR1 and CCLR0 in TCR, and of
TIOR, TIER, and TGR are valid, and input capture/compare match and interrupt functions can be
used.
This can be used for two-phase encoder pulse input.
When overflow occurs while TCNT is counting up, the TCFV flag in TSR is set; when underflow
occurs while TCNT is counting down, the TCFU flag is set.
The TCFD bit in TSR is the count direction flag. Reading the TCFD flag provides an indication of
whether TCNT is counting up or down.
Table 11.32 shows the correspondence between external clock pins and channels.
Table 11.32 Clock Input Pins in Phase Counting Mode
(1)
Figure 11.25 shows an example of the phase counting mode setting procedure.
Unit
0
1
Example of Phase Counting Mode Setting Procedure
Channels
When channel 1 or 5 is set to phase counting mode
When channel 2 or 4 is set to phase counting mode
When channel 7 or 11 is set to phase counting mode
When channel 8 or 10 is set to phase counting mode
Phase Counting Mode
Rev. 1.00 Sep. 19, 2008 Page 733 of 1342
Section 11 16-Bit Timer Pulse Unit (TPU)
A-Phase
TCLKA
TCLKC
TCLKE
TCLKG
External Clock Pins
REJ09B0467-0100
B-Phase
TCLKB
TCLKD
TCLKF
TCLKH