PCD5003AH データシートの表示（PDF） - Philips Electronics
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PCD5003AH Datasheet PDF : 44 Pages
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Philips Semiconductors
Enhanced Pager Decoder for POCSAG
Product specification
PCD5003A
Table 1 POCSAG recommended call types and function bits
BIT 20 (MSB)
0
0
1
1
BIT 21 (LSB)
0
1
0
1
CALL TYPE
numeric
alert only 1
alert only 2
alphanumeric
DATA FORMAT
4-bits per digit
−
−
7-bits per ASCII character
7.3 Error correction
Table 2 Error correction
ITEM
Preamble
Synchronization code-word
Address code-word
Message code-word
DESCRIPTION
4 random errors in 31 bits
2 random errors in 32 bits
2 random errors; plus 4-bit burst errors (optional)
2 random errors; plus 4-bit burst errors (optional)
7.4 Operating states
The PCD5003A has 2 operating states:
• ON status
• OFF status.
The operating state is determined by a Direct Control input
(DON) and bit D4 in the control register (see Table 3).
Table 3 Truth table for decoder operating status
DON INPUT
0
0
1
1
CONTROL
BIT D4
0
1
0
1
OPERATING
STATUS
OFF
ON
ON
ON
7.5 ON status
In ON status the decoder pulses the receiver and oscillator
enable outputs (respectively RXE and ROE) according to
the code structure and the synchronization algorithm. Data
received serially at the data input (RDI) is processed for
call receipt. Reception of a valid paging call is signalled to
the microcontroller by means of an interrupt signal.
The received address and message data can then be read
via the I2C-bus interface.
7.6 OFF status
In OFF status the decoder will neither activate the receiver
or oscillator enable outputs, nor process any data at the
data input. The crystal oscillator remains active to permit
communication with the microcontroller.
In both operating states an accurate timing reference is
available via the REF output. By SPF programming the
signal periodicity may be selected as 32.768 kHz, 50 Hz,
2 Hz or 1⁄60 Hz.
7.7 Reset
The decoder can be reset by applying a positive pulse on
input pin RST. A power-on reset circuit consisting of an
RC network can be connected to this input as well.
Conditions during and after a reset are described in
Chapter “Operating instructions”.
For successful reset at power-on, a HIGH level must be
present on the RST pin while the device is powering-up.
This can be applied by the microcontroller, or via a suitable
RC power-on reset circuit connected to the RST input.
Reset circuit details and conditions during and after a reset
are described in Chapter 8.
1999 Jan 08
8
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