Block Diagram Of Watch Timer - Fujitsu F2MCTM-16LX Hardware Manual

CHAPTER 15 WATCH TIMER
15.2

Block Diagram of Watch Timer

The watch timer consists of the following blocks:
• Watch timer counter
• Counter clear circuit
• Interval timer selector
• Watch timer control register (WTC)
Block Diagram of Watch Timer
Watch timer counter
× 2
SCLK
Transits to hardware standby
Transits to stop mode
Watch timer interrupt
OF : Overflow
SCLK : Subclock
The actual interrupt request number of the watch timer is as follows:
Interrupt request number: #27(1B
Watch timer counter
The watch timer counter is a 15-bit up counter that uses the subclock (SCLK) as a count clock.
Counter clear circuit
The counter-clear circuit clears the watch timer counter.
270
Figure 15.2-1 Block Diagram of Watch Timer
× 2 × 2 × 2 × 2
× 2
1 5 6
2 3 4
Power-on reset
Counter
clear circuit
WDCS SCE WTIE
Watch timer control register (WTC)
)
H
× 2 × 2 × 2 × 2 × 2 × 2
7 8 9 10 11
OF OF
OF
OF
OF
Interval timer
selector
WTOF WTR
To watchdog
timer
× 2 × 2 × 2
12 13 14 15
OF
OF
OF
To subclock oscillation
stabilization wait time
WTC2 WTC1 WTC0