Datasheet

 2017 Microchip Technology Inc. DS60001516A-page 501
SAM9G20
In addition, the maximum clock speed allowed on the TK pin is:
- Master Clock divided by 6 if Transmit Frame Synchro is input
- Master Clock divided by 2 if Transmit Frame Synchro is output
32.6.2 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 Section 32.6.4 Start.
The frame synchronization is configured setting the Transmit Frame Mode Register (SSC_TFMR). See Section 32.6.5 Frame Sync.
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 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 register, the status flag TXRDY is set in SSC_SR and additional data can be loaded in the hold-
ing register.
Figure 32-8: Transmitter Block Diagram
32.6.3 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 Section 32.6.4 Start.
The frame synchronization is configured setting the Receive Frame Mode Register (
SSC_RFMR). See Section 32.6.5 Frame Sync.
The receiver uses a shift register clocked by the receiver clock signal and the start mode selected in the SSC_RCMR. The data is trans-
ferred from the shift register depending on the data format selected.
When the receiver shift register is full, the SSC transfers this data in the holding register, the status flag RXRDY is set in SSC_SR and the
data can be read in the receiver holding register. If another transfer occurs before read of the RHR, the status flag OVERUN is set in
SSC_SR and the receiver shift register is transferred in the RHR.
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