DS1238A Dallas, DS1238A Datasheet - Page 3

• Manufacturer Part Number: DS1238A
• Description: MicroManager
• Manufacturer: Dallas

DS1238A FUNCTIONAL BLOCK DIAGRAM Figure 1
WATCHDOG TIMER
The DS1238A provides a watchdog timer function which forces the
active state when the strobe input (
is described below in NO TAG. The watchdog timeout period begins as soon as RST and
inactive. If a high-to-low transition occurs at the
and begins to timeout again. The
watchdog timer does not timeout, a high-to-low transition on
timeout of the watchdog as described in the AC Electrical Characteristics. If the watchdog timer is
allowed to time out, the
signal which indicates the watchdog status, and is activated as soon as the watchdog timer completes a
WDS
, RST, and
ST
ST
) is not stimulated for a predetermined time period. This time period
input timing is shown in NO TAG. In order to guarantee that the
RST
outputs are driven to the active state.
3 of 13
ST
input prior to timeout, the watchdog timer is reset
ST
must occur at or less than the minimum
WDS
, RST, and
RST
WDS
signals to the
is a latched
RST
DS1238A
are