HD6432670 Hitachi, HD6432670 Datasheet - Page 669

• Manufacturer Part Number: HD6432670
• Description: (HD64F267x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

14.3.1
TCNT is an 8-bit readable/writable up-counter. TCNT is initialized to H'00 when the TME bit in
TCSR is cleared to 0.
14.3.2
TCSR selects the clock source to be input to TCNT, and the timer mode.
Bit
7
6
5
Bit Name
OVF
WT/
TME
Timer Counter (TCNT)
Timer Control/Status Register (TCSR)
Initial Value
0
0
0
R/W
R/(W)*
R/W
R/W
Description
Overflow Flag
Indicates that TCNT has overflowed in interval
timer mode. Only a write of 0 is permitted, to clear
the flag.
[Setting condition]
When TCNT overflows in interval timer mode
(changes from H’FF to H’00)
When internal reset request generation is selected
in watchdog timer mode, OVF is cleared
automatically by the internal reset.
[Clearing conditions]
Cleared by reading TCSR when OVF = 1, then
writing 0 to OVF
Timer Mode Select
Selects whether the WDT is used as a watchdog
timer or interval timer.
0: Interval timer mode
When TCNT overflows, an interval timer interrupt
(WOVI) is requested.
1: Watchdog timer mode
When TCNT overflows, the
output.
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.
Rev. 2.0, 04/02, page 623 of 906
signal is