Application Notes - Renesas H8/38024 Hardware Manual

Timer G Operation Modes
Timer G operation modes are shown in table 9.12.
Table 9.12 Timer G Operation Modes
Operation Mode
Input capture Reset Functions * Functions * Functions/
TCG
Interval
ICRGF
ICRGR
TMG
Note: * When φw/4 is selected as the TCG internal clock in active mode or sleep mode, since the
system clock and internal clock are mutually asynchronous, synchronization is maintained
by a synchronization circuit. This results in a maximum count cycle error of 1/φ(s). When
φw/4 is selected as the TCG internal clock in watch mode, TCG and the noise canceler
operate on the φw/4 internal clock without regard to the φ
Note that when another internal clock is selected, TCG and the noise canceler do not
operate, and input of the input capture input signal does not result in input capture.
To operate the timer G in subactive mode or subsleep mode, select φw/4 as the TCG
internal clock and φw/2 as the subclock φ
selected, or when φw/8 or φw/4 is selected as the subclock φ
canceler do not operate.
9.5.5

Application Notes

Internal Clock Switching and TCG Operation
Depending on the timing, TCG may be incremented by a switch between different internal clock
sources. Table 9.13 shows the relation between internal clock switchover timing (by write to bits
CKS1 and CKS0) and TCG operation.
When TCG is internally clocked, an increment pulse is generated on detection of the falling edge
of an internal clock signal, which is divided from the system clock (φ) or subclock (φw). For this
reason, in a case like No. 3 in table 9.13 where the switch is from a high clock signal to a low
clock signal, the switchover is seen as a falling edge, causing TCG to increment.
Rev. 6.00, 08/04, page 284 of 628
Reset Active Sleep
Reset Functions * Functions * Functions/
Reset Functions * Functions * Functions/
Reset Functions * Functions * Functions/
Reset Functions Retained
Watch Subactive Subsleep Standby
Functions/
halted * halted *
Functions/
halted * halted *
Functions/
halted * halted *
Functions/
halted * halted *
Retained Functions Retained
subclock (φw/8, φw/4, φw/2).
SUB
. Note that when other internal clock is
SUB
SUB
Module
Standby
Functions/ Halted Halted
halted *
Functions/ Halted Halted
halted *
Functions/ Retained Retained
halted *
Functions/ Retained Retained
halted *
Retained Retained
, TCG and the noise