RL78/G1A CHAPTER 6 TIMER ARRAY UNIT
R01UH0305EJ0200 Rev.2.00 219
Jul 04, 2013
6.4 Basic Rules of Timer Array Unit
6.4.1 Basic rules of simultaneous channel operation function
When simultaneously using multiple channels, namely, a combination of a master channel (a reference timer mainly
counting the cycle) and slave channels (timers operating according to the master channel), the following rules apply.
(1) Only an even channel (channel 0, 2, 4, etc.) can be set as a master channel.
(2) Any channel, except channel 0, can be set as a slave channel.
(3) The slave channel must be lower than the master channel.
Example: If channel 2 is set as a master channel, channel 3 or those that follow (channels 3, 4, 5, etc.) can be set
as a slave channel.
(4) Two or more slave channels can be set for one master channel.
(5) When two or more master channels are to be used, slave channels with a master channel between them may not
be set.
Example: If channels 0 and 4 are set as master channels, channels 1 to 3 can be set as the slave channels of
master channel 0. Channels 5 to 7 cannot be set as the slave channels of master channel 0.
(6) The operating clock for a slave channel in combination with a master channel must be the same as that of the
master channel. The CKSmn0, CKSmn1 bits (bit 15, 14 of timer mode register mn (TMRmn)) of the slave channel
that operates in combination with the master channel must be the same value as that of the master channel.
(7) A master channel can transmit INTTMmn (interrupt), start software trigger, and count clock to the lower channels.
(8) A slave channel can use INTTMmn (interrupt), a start software trigger, or the count clock of the master channel as
a source clock, but cannot transmit its own INTTMmn (interrupt), start software trigger, or count clock to channels
with lower channel numbers.
(9) A master channel cannot use INTTMmn (interrupt), a start software trigger, or the count clock from the other higher
master channel as a source clock.
(10) To simultaneously start channels that operate in combination, the channel start trigger bit (TSmn) of the channels
in combination must be set at the same time.
(11) During the counting operation, a TSmn bit of a master channel or TSmn bits of all channels which are operating
simultaneously can be set. It cannot be applied to TSmn bits of slave channels alone.
(12) To stop the channels in combination simultaneously, the channel stop trigger bit (TTmn) of the channels in
combination must be set at the same time.
(13) CKm2/CKm3 cannot be selected while channels are operating simultaneously, because the operating clocks of
master channels and slave channels have to be synchronized.
(14) Timer mode register m0 (TMRm0) has no master bit (it is fixed as “0”). However, as channel 0 is the highest
channel, it can be used as a master channel during simultaneous operation.
The rules of the simultaneous channel operation function are applied in a channel group (a master channel and slave
channels forming one simultaneous channel operation function).
If two or more channel groups that do not operate in combination are specified, the basic rules of the simultaneous
channel operation function in 6.4.1 Basic rules of simultaneous channel operation function do not apply to the
channel groups.
Remark m: Unit number (m = 0), n: Channel number (n = 0 to 7 (however, timer input pin (TImn), timer output pin
(TOmn) : n = 0, 1, 3 to 7))