MC68HC68 MOTOROLA [Motorola, Inc], MC68HC68 Datasheet - Page 10

• Manufacturer Part Number: MC68HC68
• Description: Real-Time Clock plus RAM with Serial Interface
• Manufacturer: MOTOROLA [Motorola, Inc]

N/A = Not Applicable
MC68HC68T1
10
*** Data bit D5 is “1” for PM and “0” for AM in 12–hour mode. Data bits D7 and D6 are Don’t Cares.
** Most significant data bit, D7, is “0” for 24–hour mode and “1” for 12–hour mode. Data bit D5 is “1” for PM and “0” for AM in 12–hour mode.
* Example: 10:40:21 AM, Tuesday, June 16, 1987.
Read
$20
$21
$22
$23
$24
$25
$26
N/A
N/A
N/A
CPUR
Address Location
SCK
SS
NOTE: Reset does not occur immediately after slave select is toggled. Approximately two clock cycles later,
Service Time
Reset Time
Write
$A0
$A1
$A2
$A3
$A4
$A5
$A6
$A8
$A9
$AA
reset initiates.
Seconds
Minutes
Hours** (12 Hour Mode)
Hours (24 Hour Mode)
Day of Week (Sunday = 1)
Date of Month
Month (Jan = 1)
Year
Seconds Alarm
Minutes Alarm
Hours Alarm*** (12 Hour Mode)
Hours Alarm (24 Hour Mode)
Table 1. Clock/Calendar and Alarm Data Modes
Table 2. Watchdog Service and Reset Times
Figure 7. Watchdog Operation Waveforms
SERVICE
Function
20 ms
Min
TIME
—
50 Hz
10 ms
40 ms
Max
Decimal Range
16.7 ms
Min
—
SERVICE
0 – 59
0 – 59
1 – 12
0 – 23
1 – 31
1 – 12
0 – 99
0 – 59
0 – 59
1 – 12
0 – 23
1 – 7
TIME
60 Hz
33.3 ms
8.3 ms
Max
BCD Data Range
A1 – B2 (PM)
81 – 92 (AM)
01 – 12 (AM)
21 – 32 (PM)
00 – 59
00 – 59
00 – 23
01 – 07
01 – 31
01 – 12
00 – 99
00 – 59
00 – 59
00 – 23
15.6 ms
Min
—
XTAL
31.3 ms
7.8 ms
Max
BCD Date* Example
MOTOROLA
21
40
90
10
03
16
06
87
21
40
10
10