815
11054A–ATARM–27-Jul-11
SAM9X25
815
11054A–ATARM–27-Jul-11
SAM9X25
Figure 39-19.
FSK Modulator Output
39.7.3.6
Synchronous Receiver
In synchronous mode (SYNC = 1), the receiver samples the RXD signal on each rising edge of
the Baud Rate Clock. If a low level is detected, it is considered as a start. All data bits, the parity
bit and the stop bits are sampled and the receiver waits for the next start bit. Synchronous mode
operations provide a high speed transfer capability.
Configuration fields and bits are the same as in asynchronous mode.
illustrates a character reception in synchronous mode.
Figure 39-20.
Synchronous Mode Character Reception
39.7.3.7
Receiver Operations
When a character reception is completed, it is transferred to the Receive Holding Register
(US_RHR) and the RXRDY bit in the Status Register (US_CSR) rises. If a character is com-
pleted while the RXRDY is set, the OVRE (Overrun Error) bit is set. The last character is
transferred into US_RHR and overwrites the previous one. The OVRE bit is cleared by writing
the Control Register (US_CR) with the RSTSTA (Reset Status) bit to 1.
Manchester
encoded
data
default polarity
unipolar output
Txd
FSK Modulator
Output
Uptstream Frequencies
[F0, F0+offset]
NRZ stream
1
0
0
1
D0
D1
D2
D3
D4
D5
D6
D7
RXD
Start
Sampling
Parity Bit
Stop Bit
Example: 8-bit, Parity Enabled 1 Stop
Baud Rate
Clock
Содержание SAM9X25
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Страница 330: ...330 11054A ATARM 27 Jul 11 SAM9X25 330 11054A ATARM 27 Jul 11 SAM9X25...
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Страница 468: ...468 11054A ATARM 27 Jul 11 SAM9X25 468 11054A ATARM 27 Jul 11 SAM9X25...
Страница 532: ...532 11054A ATARM 27 Jul 11 SAM9X25 532 11054A ATARM 27 Jul 11 SAM9X25...
Страница 692: ...692 11054A ATARM 27 Jul 11 SAM9X25 692 11054A ATARM 27 Jul 11 SAM9X25...
Страница 777: ...777 11054A ATARM 27 Jul 11 SAM9X25 777 11054A ATARM 27 Jul 11 SAM9X25...
Страница 886: ...886 11054A ATARM 27 Jul 11 SAM9X25 886 11054A ATARM 27 Jul 11 SAM9X25...
Страница 962: ...962 11054A ATARM 27 Jul 11 SAM9X25 962 11054A ATARM 27 Jul 11 SAM9X25...
Страница 1036: ...1036 11054A ATARM 27 Jul 11 SAM9X25 1036 11054A ATARM 27 Jul 11 SAM9X25...
Страница 1067: ...1067 11054A ATARM 27 Jul 11 SAM9X25 1067 11054A ATARM 27 Jul 11 SAM9X25 PTZ Pause Time Zero Enable pause time zero interrupt...
Страница 1069: ...1069 11054A ATARM 27 Jul 11 SAM9X25 1069 11054A ATARM 27 Jul 11 SAM9X25 PTZ Pause Time Zero Disable pause time zero interrupt...
Страница 1071: ...1071 11054A ATARM 27 Jul 11 SAM9X25 1071 11054A ATARM 27 Jul 11 SAM9X25 PTZ Pause Time Zero Pause time zero interrupt masked...
Страница 1128: ...1128 11054A ATARM 27 Jul 11 SAM9X25 1128 11054A ATARM 27 Jul 11 SAM9X25...
Страница 1130: ...1130 11054A ATARM 27 Jul 11 SAM9X25...
Страница 1131: ...1131 11054A ATARM 27 Jul 11 SAM9X25 Revision History Doc Rev 11054A Comments Change Request Ref 1st issue...
Страница 1132: ...1132 11054A ATARM 27 Jul 11 SAM9X25...
Страница 1144: ...xii 11054A ATARM 27 Jul 11 SAM9X25...