Real-Time Clock
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
11-10
Freescale Semiconductor
Preliminary
11.2.1.8
RTC Stopwatch Minutes Register (STPWCH)
The stopwatch minutes (STPWCH) register contains the current stopwatch countdown value. When the
minute counter of the TOD clock increments, the value in this register decrements.
Figure 11-9. RTC Stopwatch Minutes Register (STPWCH)
IPSBAR
Offset: 0x03DC (STPWCH)
Access: User read/write
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
0
0
CNT
W
Reset
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
Table 11-9. STPWCH Field Descriptions
Field
Description
31–6
Reserved, should be cleared.
5–0
CNT
Stopwatch count. This field contains the stopwatch countdown value.
Note:
The stopwatch counter is decremented by the minute (MIN) tick output from the real-time clock, so the
average tolerance of the count is 0.5 minutes. For better accuracy, enable the stopwatch by polling the MIN
bit of the RTCISR register or by polling the minute interrupt service routine.