IC-HT_15 Datasheet, PDF (32/45 Pages) IC-Haus GmbH – DUAL CW LASER DIODE DRIVER

iC-HT
DUAL CW LASER DIODE DRIVER
WATCHDOG TIMER
preliminary
Rev B1, Page 32/45
The internal 200 kHz oscillator is monitored with the
Watchdog Timer (WDT).
If the oscillator remains longer than the maximum time
of tWDT (cf. Electrical Characteristics No. E03) with-
out activity an oscillator error is triggered. An oscillator
error sets OSCERR error bit to 1. The automatic offset
compensation of the laser control requires the oscilla-
tor.
The state of OSCERR is signaled at pin NCHK. The
signaling of OSCERR state can be masked with bit
MOSCERR. Setting MOSCERR to 1 masks the oscil-
lator error and OSCERR will not be signaled at NCHK.
It is possible to simulate an error of the oscillator us-
ing SOSCERR bit. If SOSCERR = 1, the oscillator er-
ror is forced. When OSCERR is set to 1 the error will
be signaled through NCHK, depending on the state of
MOSCERR.
OSCERR
0
1
Addr. 0x00; bit 6
R
Oscillator operates OK
Watchdog timeout set, oscillator fail. Cleared on
read
Table 61: Oscillator error
MOSCERR
Addr. 0x1D; bit 0
R/W 0
0
Oscillator error (watchdog) will be signaled at
NCHK
1
Oscillator error (watchdog) will not be signaled at
NCHK
Table 62: Oscillator error mask
SOSCERR
Addr. 0x1D; bit 7
R/W 0
0
No oscillator error simulated.
1
Oscillator error simulated (watchdog timeout).
Table 63: Simulate oscillator error