R01UH0823EJ0100 Rev.1.00
Page 579 of 1823
Jul 31, 2019
RX23W Group
23. Multi-Function Timer Pulse Unit 2 (MTU2a)
Figure 23.72
Relationship between Bits T3AEN and T4VEN in TITCR and Buffer Transfer-Enabled Period
(4) Complementary PWM Mode Output Protection Functions
The MTU provides the following protection functions for complementary PWM mode output.
(a) Register and Counter Miswrite Prevention Function
Access from the CPU to the mode registers, control registers, compare registers can be enabled or disabled by setting the
TRWER.RWE bit. The applicable registers are some of the registers in MTU3 and MTU4 shown below:
22 registers in total
MTU3.TCR and MTU4.TCR, MTU3.TMDR and MTU4.TMDR, MTU3.TIORH and MTU4.TIORH, MTU3.TIORL
and MTU4.TIORL, MTU3.TIER and MTU4.TIER, MTU3.TCNT and MTU4.TCNT, MTU3.TGRA and MTU4.TGRA,
MTU3.TGRB and MTU4.TGRB, MTU.TOER, MTU.TOCR1, MTU.TOCR2, MTU.TGCR, MTU.TCDR, and
MTU.TDDR
This function can disable CPU access to the mode registers, control registers, and counters to prevent miswriting due to
CPU runaway. In the access-disabled state, the applicable registers are read as undefined and writing to these registers is
ignored.
(b) Halting of PWM Output
The PWM output pins of MTU0, MTU3, and MTU4 can be set to the high-impedance state automatically.
Refer to
section 24, Port Output Enable 2 (POE2a)
, for details.
Buffer transfer-enabled period
(TITCNT1A.T3AEN bit is set to 1)
Buffer transfer-enabled period
(TITCNT1A.T4VEN bit is set to 1)
Buffer transfer-enabled period
(TITCNT1A.T3AEN and T4VEN bits are set to 1)
Skipping counter
TITCNT1A.T3ACNT[2:0] bits
MTU3.TCNT
MTU4.TCNT
TCNTSA
Skipping counter
TITCNT1A.T4VCNT[2:0] bits
Note:
The skipping count is set to three.
Buffer transfer at the crest and trough is selected.
1
2
3
0
1
2
3
0
0
1
2
3
0
1
2
0
3