MC33594FTAE Freescale Semiconductor, MC33594FTAE Datasheet - Page 5

• Manufacturer Part Number: MC33594FTAE
• Description: RF Receiver UHF RECEIVER
• Manufacturer: Freescale Semiconductor
• Type: Receiverr

Specifications of MC33594FTAE

• Package / Case: LQFP-24
• Operating Frequency: 434 MHz
• Operating Supply Voltage: 5 V
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

COMMUNICATION PROTOCOL
MANCHESTER CODING DESCRIPTION
during the second half-bit.
is allowed. In order to achieve a correct clock recovery, Manchester coded data must have a duty cycle between
45% and 55%.
PREAMBLE, ID, HEADER WORDS AND MESSAGE DESCRIPTION
Register 2. The complement of the ID word is recognized as an ID word. ID word is sent at the same data rate as
data.
Using FSK modulation, it enables data slicer reference voltage to settle and clock recovery.
Figure 4 defines the Preamble word in FSK modulation. Preamble content must be carefully defined in order not
to be decoded as an ID or Header word.
rate. This bit sequence and its complement must not be found in the sequence preamble and ID word.
Data must follow the Header without any delay.
Even in case of FSK modulation, the data must be completed by a EOM and not by simply stopping the RF
telegram. If the complement of the Header word is received, output data are complemented too.
and an EOM. The preamble is placed at the beginning of both ID and Header words.
MESSAGE PROTOCOL
Consequently, the transmitted ID burst has to be long enough to include two consecutive receiver Run cycles.
© Motorola, Inc., 2002.
Manchester coding is defined as follows: data is sent during the first half-bit, complementary data is sent
The signal average value is constant. In FSK modulation (MOD=1), clock recovery from the data stream itself
The following description applies if the Data Manager is enabled (DME=1, MOD=1).
The ID word is a Manchester coded byte whose content has been previously loaded in the Configuration
A preamble is required:
The Header word is a 4 bit Manchester coded message ‘0110’ or its complement sent at the selected data
Data are completed by a End-of-Message (EOM) word, consisting of 2 NRZ consecutive ones or zeroes.
The following example shows a complete message with Preamble, ID, Header words followed by 2 data bits,
If the receiver is continuously Sleep/Run cycling, the ID word has to be recognized to stay in Run mode.
- before ID,
- before Header if HE=1,
- before data if HE=0.
FSK Modulation:
Data slicer reference settling time
Preamble
3 ‘1’ or ‘0’ Manchester
0
1 1 0 0 1 0 0 0
at data rate
1
Freescale Semiconductor, Inc.
For More Information On This Product,
Figure 3: Manchester coding example
Figure 5: Complete message example
MOTOROLA SEMICONDUCTORS PRODUCTS
0
ID
Figure 4: Preamble definition
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0
‘1’ or ‘0’ Manchester
MC33594
1
Clock recovery
at data rate
5
1
Preamble
0
0 1
Manchester coded
Original data
Header
1
ID
0
Data
1 0
EOM
revision 1.1, 5 February 2002