ST72321M9 STMicroelectronics, ST72321M9 Datasheet - Page 50

• Manufacturer Part Number: ST72321M9
• Description: 8-bit MCU
• Manufacturer: STMicroelectronics

Specifications of ST72321M9

• Hdflash Endurance: 100 cycles, data retention
• Clock Sources: crystal/ceramic resonator oscillators, internal RC oscillator and bypass for external clock
• Four Power Saving Modes: Halt, Active-Halt,Wait and Slow
• Main Clock Controller With: Real time base, Beep and Clock-out capabilities
• Two 16-bit Timers With: 2 input captures, 2 output compares, external clock input on one timer, PWM and pulse generator modes
• 8-bit Pwm Auto-reload Timer With: 2 input captures, 4 PWM outputs, output compare and time base interrupt, external clock with event detector

ST72321M6 ST72321M9
WATCHDOG TIMER (Cont’d)
Figure 31. Exact Timeout Duration (t
50/175
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 2 ms timeout selected in MCCSR register
min0
max0
OSC2
WDGCR Register (Hex.)
(MCCSR Reg.)
Value of T[5:0] Bits in
CNT
CNT
TB1 Bit
= (LSB + 128) x 64 x t
= 16384 x t
= 125 ns if f
0
0
1
1
<
≤
MSB
-------------
MSB
-------------
00
3F
4
4
(MCCSR Reg.)
OSC2
OSC2
TB0 Bit
THEN
ELSE
THEN
ELSE
0
1
0
1
=8 MHz
t
t
max
Min. Watchdog
min
t
t
Timeout (ms)
max
OSC2
min
=
=
1.496
t
Selected MCCSR
128
=
=
min
t
t
min0
max0
t
t
min0
max0
Timebase
10ms
25ms
2ms
4ms
min
+
+
+
+
16384
and t
16384
16384
16384
Max. Watchdog
Timeout (ms)
max
×
128.552
×
×
×
2.048
t
⎛
⎝
max
⎛
⎝
CNT
MSB
CNT
)
CNT
min
CNT
max
20
49
4
8
):
–
):
–
×
×
4CNT
---------------- -
MSB
4CNT
---------------- -
LSB
t
MSB
t
osc2
35
54
59
53
osc2
⎞
⎠
⎞
⎠
+
+
(
(
192
192
+
+
LSB
LSB
)
)
×
×
64
64
×
×
4CNT
---------------- -
MSB
4CNT
---------------- -
MSB
×
×
t
t
osc2
osc2