t4225b ATMEL Corporation, t4225b Datasheet - Page 13

• Manufacturer Part Number: t4225b
• Description: Low-cost Time-code Receiver
• Manufacturer: ATMEL Corporation

Rev. A3, 03-Dec-98
Information on the British Transmitter
Station: MSF
Frequency 60 kHz
Transmitting power 50 kW
Location: Teddington, Middlesex
Modulation
The carrier amplitude is switched off at the beginning of
each second for a period of 100 ms (binary zero) or
200 ms (binary one).
0
Example:
March 1993
seconds
5
500 ms
Switch over to
the next time frame
0
10
17
500 ms
80
15
18
1
40
20
19
year
20
Time frame 1 minute
20
25
( index count 1 second)
month
10
21
year
30
day of
month
8
Figure 24.
22
35
day
of
week
4
Geographical coordinates: 52 __ 22’N, 01 _ 11’W
Time of transmission: permanent, except the first
Tuesday of each month from 10.00 h to 14.00 h.
Time-Code Format
The time-code format consists of 1-minute time frames.
A time frame contains BCD-coded information of year,
month, calendar day, day of the week, hours and minutes.
At the switch-over to the next time frame, the carrier
amplitude is switched off for a period of 500 ms.
The prescence of the fast code during the first 500 ms at
the beginning of the minute is not guaranteed. The trans-
mission rate is 100 bits/s and the code contains
information of hour, minute, day and month.
23
40
hour
2
24
45
1
minute
25
Parity
check
bits
50
10
26
55
8
27
month
0
4
minute
identifier
BST
hour + minute
day of week
day + month
year
BST 7 GMT change
impending
T4225B
28
Time frame
5
2
29
93 7528
10
1
13 (16)
30