ST72F321AR9TA STMicroelectronics, ST72F321AR9TA Datasheet - Page 54

• Manufacturer Part Number: ST72F321AR9TA
• Description: IC MCU 8BIT 60KB FLASH 64-TQFP
• Manufacturer: STMicroelectronics
• Series: ST7r

Specifications of ST72F321AR9TA

• Core Processor: ST7
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SCI, SPI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 48
• Program Memory Size: 60KB (60K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 3.8 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

ST72321Rx ST72321ARx ST72321Jx
WATCHDOG TIMER (Cont’d)
Figure 34. Exact Timeout Duration (t
54/193
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
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
= 125ns 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
Min. Watchdog
t
max
t
min
Timeout (ms)
OSC2
t
max
min
1.496
=
=
t
Selected MCCSR
128
min
=
=
t
t
min0
max0
t
t
Timebase
min0
max0
10ms
25ms
2ms
4ms
min
+
+
+
+
and t
16384
16384
16384
16384
Max. Watchdog
Timeout (ms)
max
128.552
×
×
×
2.048
t
×
⎛
⎝
max
⎛
⎝
MSB
CNT
CNT
)
min
CNT
CNT
max
20
49
4
8
):
):
–
×
–
×
t
4CNT
---------------- -
LSB
MSB
t
osc2
4CNT
---------------- -
35
54
osc2
MSB
59
53
⎞
⎠
⎞
⎠
+
+
(
(
192
192
+
+
LSB
LSB
)
) 64
×
×
64
×
×
4CNT
---------------- -
MSB
4CNT
---------------- -
MSB
×
×
t
osc2
t
osc2