AN2262 Motorola / Freescale Semiconductor, AN2262 Datasheet - Page 19

• Manufacturer Part Number: AN2262
• Description: Wireless HC08 Modem
• Manufacturer: Motorola / Freescale Semiconductor

Software
Application
Software Basics
MOTOROLA
FRAME #1
FRAME #2
SCI
RF-08
This RF protocol defines only the physical appearance of RF frames in order to
be correctly transferred using the MC33493 and MC33591/3 chips. The pay-
load is then really application specific and is described in
This section provides the ‘transparent’ software description for the RF-08
board.
The software described here provides a very basic function. It is called
‘transparent mode’. The data received from the SCI (serial) line is formatted
into frames and the frames are sent out via RF. See
In the opposite direction, if such a frame is received via RF its consistency is
checked and the data is re-transmitted to the serial line (if correct). Such
operation allows the use of simple packet (frame) oriented protocols through an
RF communication channel. All frames are secured with a so-called cyclic
redundancy code field which contains information that is used on the recipient’s
side to check whether or not the received data is consistent. If the frame is
corrupted during the RF transfer it is discarded. Only good frames are
transferred over the complete system.
RF
RF TRANSMISSION
SPI DATA
SPI CLOCK
SETTLING
AGC
Figure 10. Frame Handling
LEN
HEADER
Wireless HC08 Modem
FRAME #1
LEN
CRC
FRAME #2
Figure 9. RF Protocol
PAY-LOAD
CRC
RF
RF-08
Figure
EOM
RF-08
10.
SCI
Protocol.
FRAME #1
FRAME #2
AN2262/D
Software
19