SAB80C515A-5 Datasheet, PDF (51/108 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller Family

On-Chip Peripheral Components
Detailed Description of the Oscillator Watchdog Unit
Figure 5-8 shows the block diagram of the oscillator watchdog unit. It consists of an internal RC
oscillator which provides the reference frequency for the comparison with the frequency of the on-
chip oscillator.
Figure 5-8
Oscillator Watchdog Unit
Special Function Register IP0 (Address 0A9H)
Bit No.
086H
MSB
7
6
OWDS WDTS
5
IP0.5
4
IP0.4
3
IP0.3
2
IP0.2
These bits are not used for Watchdog Timer
1
IP0.1
LSB
0
IP0.0 IPO
Bit
OWDS
Function
Oscillator watchdog timer status flag.
Set by hardware when an oscillator watchdog reset occurred. Can be
cleared and set by software.
Reset value of IP0 is 00H.
Semiconductor Group
5-18