585
32072H–AVR32–10/2012
AT32UC3A3
Figure 25-46. Start Frame Delimiter
Manchester Drift Compensation
The Drift Compensation bit (MAN.DRIFT) enables a hardware drift compensation and recovery
system that allows for sub-optimal clock drifts without further user intervention. Drift compensa-
tion is only available in 16x oversampling mode (MR.OVER is zero). If the RXD event is one 16
th
clock cycle from the expected edge, it is considered as normal jitter and no corrective action will
be taken. If the event is two to four 16
th
’s early, the current period will be shortened by a 16
th
. If
the event is two to three 16
th
’s after the expected edge, the current period will be prolonged by a
16
th
.
Figure 25-47. Bit Resynchronization
25.6.16.2
Manchester Decoder
The Manchester decoder can detect selectable preamble sequences and start frame delimiters.
The Receiver Manchester Polarity bit in the
“Manchester Configuration Register”
(MAN.RX_MPOL) selects input stream polarity. The Receiver Preamble Length field
(MAN.RX_PL) specifies the length characteristics of detectable preambles. If MAN.RX_PL is
zero, the preamble pattern detection will be disabled. The Receiver Preamble Pattern field
(MAN.RX_PP) selects the pattern to be detected. See
for available preamble pat-
illustrates two types of Manchester preamble pattern mismatches.
Manchester
encoded
data
Txd
SFD
DATA
One bit start frame delimiter
Preamble Length
is set to 0
Manchester
encoded
data
Txd
SFD
DATA
Command Sync
start frame delimiter
Manchester
encoded
data
Txd
SFD
DATA
Data Sync
start frame delimiter
RXD
Oversampling
16x Clock
Sampling
point
Expected edge
Tolerance
Synchro.
Jump
Sync
Jump
Synchro.
Error
Synchro.
Error
Summary of Contents for AT32UC3A3128
Page 61: ...61 32072H AVR32 10 2012 AT32UC3A3 PLLEN PLL Enable 0 PLL is disabled 1 PLL is enabled...
Page 592: ...592 32072H AVR32 10 2012 AT32UC3A3 Manchester Configuration Register on page 614...
Page 989: ...989 32072H AVR32 10 2012 AT32UC3A3 37 2 Package Drawings Figure 37 1 TFBGA 144 package drawing...
Page 991: ...991 32072H AVR32 10 2012 AT32UC3A3 Figure 37 3 VFBGA 100 package drawing...