MC33696MOD434EV Freescale Semiconductor, MC33696MOD434EV Datasheet - Page 18

• Manufacturer Part Number: MC33696MOD434EV
• Description: MCU, MPU & DSP Development Tools MC33696 (ECHO) RF C EVAL
• Manufacturer: Freescale Semiconductor

Specifications of MC33696MOD434EV

• Processor To Be Evaluated: MC9S08RG60
• Interface Type: RS-232
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Receive Mode
12.2.3.3 HEADER
The HEADER defines the beginning of the message, as it is compared with the HEADER register. Its
length is variable, defined by the HDL[1:0] bits. The complement of the header is also recognized as the
header—in this case, output data is complemented. The header and its complement should not be part of
the ID.
The ID and the header are sent at the same data rate as data.
12.2.3.4 Data and EOM
The data must follow the header, with no delay.
The message is completed with an end-of-message (EOM), consisting of two consecutive NRZ ones or
zeroes (i.e., a Manchester code violation). Even in the case of FSK modulation, data must conclude with
an EOM, and not simply by stopping the RF transmission.
12.2.4 State Machine in Receive Mode When DME=1
When the strobe oscillator is enabled (SOE = 1), the receiver is continuously cycling on/off. The ID must
be recognized for the receiver to stay on. Consequently, the transmitted ID burst must be long enough to
include two consecutive receiver-on cycles.
When the strobe oscillator is not enabled (SOE = 0), these timing constraints must be respected by the
external control applied to pin STROBE.
Figure 11
oscillator (SOE=1) or externally by the MCU (SOE=0).
Two different processes are possible, as determined by the values of the SOE bit.
12.2.4.1 Data Manager Enabled and Strobe Oscillator Enabled
Figure 11
configuration, the receiver is controlled internally by the strobe oscillator. However, external control via
the STROBE pin is still possible, and overrides the strobe oscillator command.
18
Receiver
Receiver
Output
Output
Signal
Signal
Status
Status
SPI
SPI
RF
RF
shows the correct detection of an ID when STROBE is controled internally using the strobe
shows the state diagram when the data manager and the strobe oscillator are enabled. In this
On Time
On Time
On
On
Preamble
Preamble
Figure 10. Complete Transmission with ID Detection
ID
ID
Off Time
Off Time
ID
ID
Off
Off
MC33696 Data Sheet, Rev. 12
ID
ID
ID Field
ID Field
ID
ID
ID
ID
Detected
Detected
ID
ID
ID
ID
ID
ID
Header
Header
On
On
Freescale Semiconductor
Data
Data
Data
Data
EOM
EOM
Off
Off