ST7FMC2N6B6(2004) View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
ST7FMC2N6B6
(Rev.:2004)
(Rev.:2004)
STMicroelectronics
ST7FMC2N6B6 Datasheet PDF : 294 Pages
| |||
ST7MC1/ST7MC2
WATCHDOG TIMER (Cont’d)
Figure 34. Exact Timeout Duration (tmin and tmax)
WHERE:
tmin0 = (LSB + 128) x 64 x tOSC2
tmax0 = 16384 x tOSC2
tOSC2 = 125ns if fOSC2=8 MHz
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
TB1 Bit
TB0 Bit
(MCCSR Reg.) (MCCSR Reg.)
0
0
0
1
1
0
1
1
Selected MCCSR
Timebase
2ms
4ms
10ms
25ms
MSB
4
8
20
49
LSB
59
53
35
54
To calculate the minimum Watchdog Timeout (tmin):
IF CNT <
M------S----B---
4
THEN tmin = tm in0 + 16384 × CNT × tosc2
ELSE tmin = tm in0 +
16384
×
C
N
T
–
4----C-----N-----T--
MSB
+
(192
+
LSB)
×
64
×
4----C-----N-----T--
MSB
× tosc2
To calculate the maximum Watchdog Timeout (tmax):
IF CNT ≤
M------S----B---
4
THEN tmax = tm ax0 + 16384 × CNT × tosc2
ELSE tmax = tm ax0 +
16384 × C NT –
4----C-----N-----T--
MSB
+
(192
+
LSB)
×
64
×
4----C-----N-----T--
MSB
× tosc2
Note: In the above formulae, division results must be rounded down to the next integer value.
Example:
With 2ms timeout selected in MCCSR register
Value of T[5:0] Bits in
WDGCR Register (Hex.)
00
3F
Min. Watchdog
Timeout (ms)
tmin
1.496
128
Max. Watchdog
Timeout (ms)
tmax
2.048
128.552
59/294
1
Share Link: 