Atmel AT90PWM2 Manual page 215

19.3.4.1 Manchester Framing error detection
AT90PWM2/3/2B/3B
216
Figure 19-4. Manchester Decoder operation
Data Clock
Manchester
Data
Manchester
Decoder
Counter
Detection
Window
Internal
Manchester
Clock
Decoded
Data
Note: N1 = MBURR[H:L]/2
When configured in Manchester mode, the framing error (FE) of the USCRA register is not used,
the EUSART generates a dedicated Frame Error Manchester (FEM) when a data data bit is not
detected during the detection window (See
Start Bit
Bit 1
N1 N2
N1/2 N2/4
Start Bit
Figure 19-5).
Bit 3
Bit 2
Delayed edge
N3
N2/2 N3/4 N3/2
4317I–AVR–01/08
N4
N4/4