stlc5464 STMicroelectronics, stlc5464 Datasheet - Page 36

• Manufacturer Part Number: stlc5464
• Description: Multi-hdlcwith Switching Matrix Associated
• Manufacturer: STMicroelectronics

STLC5464
III - FUNCTIONAL DESCRIPTION (continued)
Figure 26 : The Three Circular Interrupt Memories
III.9 - Watchdog
This function is used to control the activity of the
application. It is composed of a counter which
counts down from an initial value loaded in the
Timer register by the microprocessor.
If the microprocessor doesn’t reset this counter
before it is totally decremented, the external Pin
WDO is activated ; this signal can be used to reset
the microprocessor and all the application.
The initial time value of the counter is programma-
ble from 0 to 15s in increments of 0.25ms.
At the reset of the component, the counter is auto-
matically initialized by the value corresponding to
512ms which are indicated in the Timer register.
36/83
IBA + 254
IBA
INITIALIZATION
BLOC K
IBA + 256
INTER RUPT QUEUE
HDLC (Tx a nd Rx)
Que ue Size
IBA + 256
The microprocessor must put WDR (IDCR Regis-
ter) to”1” to reset this counter and to confirm that
the application started correctly.
In the reverse case, the WDO signal could be used
to reset the board a second time.
III.10 - Reset
There are two possibilities to reset the circuit :
- by software,
- by hardware.
Each programmable register receives its default
value. After that, the default value of each data
register is stored in the associatedmemory except
for Time slot Assigner memory.
+ HDLC
INTER RUP TQUEUE
MON (Rx)
Que ue S ize
Que ue S ize
IBA + 256
+ HDLC
+ MON
INTER RUP T QUEUE
C/I (Rx)