Freescale Semiconductor MPC5200B ユーザーズマニュアル
Real-Time Clock
MPC5200B Users Guide, Rev. 1
Freescale Semiconductor
7-67
7.6.3.1
RTC Time Set Register—MBAR + 0x0800
•
(0x0808)
•
,
read-only
•
(0x080C)
•
•
RTC Current Time Register (0x0810)
, read-only
Table 7-56. RTC Time Set Register
msb 0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
Reserved
set_tim
e
pa
use_t
ime
Reserved
SlctH
our
C24Hour_set
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31 lsb
R
Reserved
Minute_set
Reserved
Second_set
W
RESET:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Name
Description
0:5
—
Reserved
6
set_time
A bit used in conjunction with pause_time bit (below) to cause a new time to be programmed
into the RTC. After a proper software sequence, the values in the *_set fields below are
loaded.
into the RTC. After a proper software sequence, the values in the *_set fields below are
loaded.
The proper software sequence is:
1.
Write register with pause_time 1 and set_time 0
2.
Write register with pause_time 1 and set_time 1
3.
Write register with pause_time 1 and set_time 0
4.
Write register with pause_time 0 and set_time 0
At completion of Step 4, RTC is updated with the new time.
The C24Hour_set, Minute_set, and the Second_set fields should remain consistent values
throughout the four steps (i.e., at the desired new time values).
throughout the four steps (i.e., at the desired new time values).
Note: Read-modify-write operations may disrupt this procedure, it is advised that four
simple writes occur. Byte writes to this byte are also acceptable.
simple writes occur. Byte writes to this byte are also acceptable.
7
pause_time
Used with set_time above to perform time update. Must be zero for normal operation.
8:9
—
Reserved
10
SlctHour
This bit determines the hour output format.
• low bit = 24-hour format
• high bit = 12-hour format with AM/PM
Note: This bit does NOT affect time set procedure, it only affects how the Hour Status field
is presented.
• high bit = 12-hour format with AM/PM
Note: This bit does NOT affect time set procedure, it only affects how the Hour Status field
is presented.
11:15
C24Hour_set
Hour in 24-hour format written in RTC after successful state machine transition by set_time
and pause_time bits.
and pause_time bits.
Note: This field is always written with 24-Hour format, it is NOT affected by SlctHour bit
above.
above.
16:17
—
Reserved