
1997 Mar 04
21
Philips Semiconductors
Product specification
POCSAG Paging Decoder
PCF5001
7.15
Serial communication call data format
Table 4
Address word format
Table 5
Message word format
Note
1.
Bit 7 = 1, if message codeword could not be corrected.
Table 6
Termination word format
Note
1.
Bit 7 = 1, if call termination on error.
FUNCTION CODE
CALL ADDRESS
BIT 4
SYNC STATUS
DUPLEX CALL
BIT 7
BIT 0 (LSB)
BIT 1 (MSB)
BIT 2
BIT 3
RIC
BIT 5
BIT 6
Bit 21 of
address
codeword
bit 20 of
address
codeword
0
0
1
1
0
1
0
1
A
B
C
D
1
0 = Data
Receive;
1 = Data fail
1 = Duplex Call
time-out active
0
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
(1)
LSB
message bits
MSB
error flag
BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
(1)
0
0
1
0
0
0
0
error flag
7.16
Data conversion
The PCF5001 automatically converts message codewords
received in numeric or alphanumeric format into ASCII
format. Depending on SPF13 and the function bit setting in
the received address codeword a conversion takes place
as shown in Table 7.
When a conversion from alphanumeric format to ASCII
takes place, the received message codewords are split
into message blocks, seven bits in length. After adding the
error flag they are transferred as message words.
When a conversion from numeric format to ASCII takes
place, the received message codewords are split into
blocks, four bits in length. Each four bit block is converted
to a seven bit block as shown in Table 8. After adding the
error flag they are transferred as message words.
Table 7
Message data conversion
Note
1.
X = don’t care.
SPF13
FUNCTION BITS
MESSAGE FORMAT
BIT 20 (MSB)
X
(1)
0
X
(1)
1
BIT 21 (LSB)
X
(1)
0
1
X
(1)
0
1
1
1
numeric
numeric
alphanumeric
alphanumeric