HD404344R Datasheet, PDF (52/102 Pages) Renesas Technology Corp – 4-bit microcomputer has an A/D converter

HD404344R Series/HD404394 Series
Timers
The MCU has two built-in timers, B and C. The functions of each timer are listed in table 19.
Table 19 Timer Functions
Functions
Clock source
Timer functions
Timer output
Prescaler S
External event
Free-running
Event counter
Reload
Watchdog
PWM
Timer B
Available
Available
Available
Available
Available
—
—
Timer C
Available
—
Available
—
Available
Available
Available
Timer B
Timer B is an 8-bit multifunction timer that includes free-running, reload, and event counter features. These
are described as follows.
• By setting timer mode register B1 (TMB1: $009), one of seven internal clocks supplied from prescaler
S can be selected, or timer B can be used as an external event counter.
• By setting timer mode register B2 (TMB2: $026), timer B can be incremented by each edge detector of
input signals at pin EVNB.
• By setting timer write register BL, BU (TWBL, TWBU: $00A, $00B), timer counter B (TCB) can be
written to during reload timer operation.
• By setting timer read register BL, BU (TRBL, TRBU: $00A, $00B), the contents of timer counter B can
be read out.
Timer B Operation
• Free-running/reload timer operation: The selection of the free-running/reload timer, input clock source,
and prescaler division ratio is done by timer mode register B1 (TMB1: $009).
Timer B is initialized to the data which is written to timer write register B (TWBL: $00A, TWBU:
$00B) by software. The data is then incremented in steps of 1 by using the input clock. If the clock
input is continued after timer B is set to $FF, an overflow occurs. Timer B then begins counting again,
setting the timer to the value in timer write register B (TWBL: $00A, TWBU: $00B) when the reload
timer is selected, or reset to $00 when the free-running timer is selected.
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