DS785UM1
17-15
Copyright 2007 Cirrus Logic
IrDA
EP93xx User’s Guide
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Figure 17-3. 4PPM Modulation Example
17.5.1.2 4.0 Mbps FIR Frame Format
When the 4.0 Mbps transmission rate is used, the high-speed serial/parallel (FIR) interface
within the FIR is used along with the 4PPM bit encoding. The high-speed frame format shown
in
, is similar to the SDLC format with several minor modifications: the start/stop
flags and CRC are twice as long and instead of one start flag, a preamble and start flag of
differing length are used.
Figure 17-4. IrDA (4.0 Mbps) Transmission Format
64
symbols
8
symbols
4 DDs
(8 bits)
4 DDs
(8 bits)
8180 DDs max
(2045 bytes)
16 DDs
(32 bits)
8 symbols
Preamble
Start Flag
Address
Control
(optional)
Data CRC-32
Stop
Flag
Start Flag
|0000|1100|0000|1100|0110|0000|0110|0000|
|0000|1100|0000|1100|0000|0110|0000|0110|
Stop Flag
Preamble
|1000|0000|1010|1000|... repeated 16 times
Receive data sample counter frequency = 6x pulse width, each time-slot sampled on third clock.
Summary of Contents for EP93 Series
Page 28: ...P 6 DS785UM1 Copyright 2007 Cirrus Logic Preface EP93xx User s Guide PP P ...
Page 162: ...5 36 DS785UM1 Copyright 2007 Cirrus Logic System Controller EP93xx User s Guide 55 5 ...
Page 576: ...15 18 DS785UM1 Copyright 2007 Cirrus Logic UART2 EP93xx User s Guide 1515 15 ...
Page 634: ...17 38 DS785UM1 Copyright 2007 Cirrus Logic IrDA EP93xx User s Guide 1717 17 ...
Page 648: ...19 6 DS785UM1 Copyright 2007 Cirrus Logic Watchdog Timer EP93xx User s Guide 1919 19 ...
Page 688: ...21 32 DS785UM1 Copyright 2007 Cirrus Logic I2S Controller EP93xx User s Guide 2121 21 ...
Page 790: ...27 20 DS785UM1 Copyright 2007 Cirrus Logic IDE Interface EP93xx User s Guide 2727 27 ...
Page 808: ...28 18 DS785UM1 Copyright 2007 Cirrus Logic GPIO Interface EP93xx User s Guide 2828 28 ...