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2 timer control/status register (tcsr) – Renesas H8S/2111B User Manual

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Rev. 1.00, 05/04, page 224 of 544

11.3.2 Timer

Control/Status Register (TCSR)

TCSR selects the clock source to be input to TCNT, and the timer mode.

• TCSR_0

Bit Bit

Name

Initial
Value R/W Description

7 OVF 0 R/(W)*

1

Overflow

Flag

Indicates that TCNT has overflowed (changes from
H'FF to H'00).

[Setting condition]

When TCNT overflows (changes from H'FF to H'00)

However, when internal reset request generation is
selected in watchdog timer mode, OVF is cleared
automatically by the internal reset.

[Clearing conditions]

• When TCSR is read when OVF = 1*

2

, then 0 is

written to OVF

• When 0 is written to TME

6 WT/

IT

0

R/W

Timer Mode Select

Selects whether the WDT is used as a watchdog timer
or interval timer.

0: Interval timer mode

1: Watchdog timer mode

5 TME 0 R/W

Timer

Enable

When this bit is set to 1, TCNT starts counting.

When this bit is cleared, TCNT stops counting and is
initialized to H'00.

4 —

0 R/(W)

Reserved

The initial value should not be modified.

3 RST/

NMI 0

R/W

Reset or NMI

Selects to request an internal reset or an NMI interrupt
when TCNT has overflowed.

0: An NMI interrupt is requested

1: An internal reset is requested

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