Datasheet

349
6120F–ATARM–03-Oct-06
AT91SAM7X512/256/128 Preliminary
31.6.2 Transmitter Operations
A transmitted frame is triggered by a start event and can be followed by synchronization data
before data transmission.
The start event is configured by setting the Transmit Clock Mode Register (SSC_TCMR). See
“Start” on page 350.
The frame synchronization is configured setting the Transmit Frame Mode Register
(SSC_TFMR). See “Frame Sync” on page 352.
To transmit data, the transmitter uses a shift register clocked by the transmitter clock signal
and the start mode selected in the SSC_TCMR. Data is written by the application to the
SSC_THR register then transferred to the shift register according to the data format selected.
When both the SSC_THR and the transmit shift register are empty, the status flag TXEMPTY
is set in SSC_SR. When the Transmit Holding register is transferred in the Transmit shift reg-
ister, the status flag TXRDY is set in SSC_SR and additional data can be loaded in the holding
register.
Figure 31-8. Transmitter Block Diagram
31.6.3 Receiver Operations
A received frame is triggered by a start event and can be followed by synchronization data
before data transmission.
The start event is configured setting the Receive Clock Mode Register (SSC_RCMR). See
“Start” on page 350.
The frame synchronization is configured setting the Receive Frame Mode Register
(SSC_RFMR). See “Frame Sync” on page 352.
The receiver uses a shift register clocked by the receiver clock signal and the start mode
selected in the SSC_RCMR. The data is transferred from the shift register depending on the
data format selected.
Transmit Shift Register
Start
Selector
SSC_TSHRSSC_THR
Transmitter Clock
TD
SSC_TFMR.FSLENSSC_TFMR.DATLEN
SSC_CR.TXEN
SSC_CR.TXDIS
SSC_TCMR.STTDLY
SSC_TFMR.FSDEN
SSC_TFMR.DATNB
SSC_SR.TXEN
SSC_TFMR.DATDEF
SSC_TFMR.MSBF
SSC_TCMR.STTDLY
SSC_TFMR.FSDEN
0
1
10
RF
TF