U4223B Datasheet, PDF (13/18 Pages) ATMEL Corporation – Time-Code Receiver with A/D Converter

U4223B
Information on the German Transmitter
Station: DCF 77,
Frequency 77.5 kHz,
Transmitting power 50 kW
Location: Mainflingen/Germany,
Geographical coordinates: 50_ 0.1’N, 09_ 00’E
Time of transmission: permanent
Time frame 1 minute
( index count 1 second )
Time frame
0 5 10 15 20 25 30 35 40 45 50 55 0 5 10
coding
when
required
minutes
hours calendar day month year
day of
the
week
Example:19.35 h
s 1 2 4 8 10 20 40 P1 1 2 4 8 10 20 P2
seconds 20
21 22 23
Start Bit
24 25
minutes
26 27 28
Figure 24.
29 30 31 32 33 34 35
hours
Parity Bit P1
Parity Bit P2
Modulation
The carrier amplitude is reduced to 25% at the beginning
of each second for a period of 100 ms (binary zero) or
200 ms (binary one), except the 59th second.
Time-Code Format (based on
Information of Deutsche Bundespost)
The time-code format consists of 1-minute time frames.
There is no modulation at the beginning of the 59th
second to indicate the switch over to the next 1-minute
time frame. A time frame contains BCD-coded infor-
mation of minutes, hours, calendar day, day of the week,
month and year between the 20th second and 58th second
of the time frame, including the start bit S (200 ms) and
parity bits P1, P2 and P3. Furthermore, there are 5 addi-
tional bits R (transmission by reserve antenna), A1
(announcement of change-over to summer time), Z1 (dur-
ing summer time 200 ms, otherwise 100 ms), Z2 (during
standard time 200 ms, otherwise 100 ms) and A2
(announcement of leap second) transmitted between the
15th second and 19th second of the time frame.
Rev. A7, 06-Mar-01
13 (18)