SH7201 Datasheet, PDF (513/1196 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 12 Multi-Function Timer Pulse Unit 2 (MTU2)
(3) Phase Counting Mode Application Example:
Figure 12.34 shows an example in which channel 1 is in phase counting mode, and channel 1 is
coupled with channel 0 to input servo motor 2-phase encoder pulses in order to detect position or
speed.
Channel 1 is set to phase counting mode 1, and the encoder pulse A-phase and B-phase are input
to TCLKA and TCLKB.
Channel 0 operates with TCNT counter clearing by TGRC_0 compare match; TGRA_0 and
TGRC_0 are used for the compare match function and are set with the speed control period and
position control period. TGRB_0 is used for input capture, with TGRB_0 and TGRD_0 operating
in buffer mode. The channel 1 counter input clock is designated as the TGRB_0 input capture
source, and the pulse widths of 2-phase encoder 4-multiplication pulses are detected.
TGRA_1 and TGRB_1 for channel 1 are designated for input capture, and channel 0 TGRA_0 and
TGRC_0 compare matches are selected as the input capture source and store the up/down-counter
values for the control periods.
This procedure enables the accurate detection of position and speed.
TCLKA
TCLKB
Edge
detection
circuit
TCNT_1
Channel 1
TGRA_1
(speed period capture)
TGRB_1
(position period capture)
TCNT_0
TGRA_0
+
(speed control period)
-
TGRC_0
(position control period)
+
-
TGRB_0 (pulse width capture)
TGRD_0 (buffer operation)
Channel 0
Figure 12.34 Phase Counting Mode Application Example
Rev. 2.00 Sep. 07, 2007 Page 485 of 1164
REJ09B0321-0200