ST10 STMICROELECTRONICS [STMicroelectronics], ST10 Datasheet - Page 26

• Manufacturer Part Number: ST10
• Description: 16-BIT MCU WITH 32K BYTE ROM
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST10C167
XIV - CAN MODULE
The integrated CAN module handles the com-
pletely autonomous transmission and reception of
CAN frames in accordance with the CAN specifi-
cation V2.0 part B (active) i.e. the on-chip CAN
module can receive and transmit standard frames
with 11-bit identifiers as well as extended frames
with 29-bit identifiers.
The CAN module provides full CAN functionality
on up to 15 message objects. Message object 15
can be configured for basic CAN functionality.
Both modes provide separate masks for accep-
tance filtering, allowing a number of identifiers in
full CAN mode to be accepted and disregarding a
number of identifiers in basic CAN mode.
All message objects can be updated independent
from other objects and are equipped for the maxi-
mum message length of 8 Byte.
The bit timing is derived from the XCLK and is pro-
grammable up to a data rate of 1M Baud. The
CAN module uses two pins to interface to a bus
transceiver.
Table 12 : Watchdog time range for 25MHz CPU clock
26/65
Reload value in WDTREL
FF
00
H
H
2 (WDTIN = ‘0’)
20.48 s
5.24ms
XV - WATCHDOG TIMER
The Watchdog Timer is a fail-safe mechanism
which prevents the microcontroller from malfunc-
tioning for long periods of time. The Watchdog
Timer is always enabled after a reset of the chip
and can only be disabled in the time interval until
the EINIT (end of initialization) instruction has
been executed. Therefore, the chip start-up pro-
cedure is always monitored. The software must
be designed to service the watchdog timer before
it overflows. If, due to hardware or software
related failures, the software fails to do so, the
watchdog timer overflows and generates an inter-
nal hardware reset. It pulls the RSTOUT pin low in
order to allow external hardware components to
be reset.
The Watchdog Timer is 16-bit, clocked with the
system clock divided by 2 or 128. The high Byte of
the watchdog timer register can be set to a
pre-specified reload value (stored in WDTREL).
Each time it is serviced by the application soft-
ware, the high Byte of the watchdog timer is
reloaded. For security, rewrite WDTCON each
time before the watchdog timer is serviced
Prescaler for f
CPU
128 (WDTIN = ‘1’)
1.31ms
336ms