ST72321AR9-Auto STMicroelectronics, ST72321AR9-Auto Datasheet - Page 79

• Manufacturer Part Number: ST72321AR9-Auto
• Description: 8-bit MCU for automotive with 60 Kbyte Flash, 10-bit ADC, timers, SPI, SCI and I2C interfaces
• Manufacturer: STMicroelectronics

Specifications of ST72321AR9-Auto

• Hdflash Endurance: 100 cycles, data retention 20 years
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• 4 Power Saving Modes: Halt, Active Halt, Wait and Slow

ST72321xx-Auto
Figure 33. Exact timeout duration (t
WHERE:
t
t
t
CNT = Value of T[5:0] bits in the WDGCR register (6 bits)
MSB and LSB are values from the table below depending on the timebase selected by the TB[1:0] bits
in the MCCSR register
To calculate the minimum Watchdog Timeout (t
IF
To calculate the maximum Watchdog Timeout (t
IF
Note: In the above formulae, division results must be rounded down to the next integer value.
Example:
With 2ms timeout selected in MCCSR register
min0
max0
OSC2
(MCCSR reg.)
WDGCR register (Hex.)
Value of T[5:0] bits in
CNT
CNT
TB1 bit
= (LSB + 128) x 64 x t
= 16384 x t
= 125ns if f
0
0
1
1

<
MSB
-------------
MSB
-------------
3F
00
4
4
(MCCSR reg.)
OSC2
OSC2
TB0 bit
THEN
ELSE
THEN
ELSE
0
1
0
1
= 8 MHz
t
Min. Watchdog
t
max
t
min
Timeout (ms)
OSC2
t
max
min
1.496
=
=
t
Selected MCCSR
128
min
Doc ID 13829 Rev 1
=
=
t
t
min0
max0
t
t
timebase
min0
max0
10ms
25ms
2ms
4ms
+
+
+
+
16384
16384
16384
16384
min
Max. Watchdog
Timeout (ms)
128.552
and t



2.048
t



max


MSB
CNT
CNT
min
CNT
CNT
max
20
49
4
8
):
max
):
–

–

t
4CNT
---------------- -
LSB
osc2
MSB
t
4CNT
---------------- -
59
53
35
54
osc2
MSB
)




+
+


192
192
+
+
LSB
LSB
Watchdog timer (WDG)
 64



64


4CNT
---------------- -
MSB
4CNT
---------------- -
MSB


t
osc2
t
osc2
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