Datasheet

 2017 Microchip Technology Inc. DS60001516A-page 505
SAM9G20
32.6.7 Data Format
The data framing format of both the transmitter and the receiver are programmable through the Transmitter Frame Mode Register
(SSC_TFMR) and the Receiver Frame Mode Register (SSC_RFMR). In either case, the user can independently select:
• the event that starts the data transfer (START)
• the delay in number of bit periods between the start event and the first data bit (STTDLY)
• the length of the data (DATLEN)
• the number of data to be transferred for each start event (DATNB).
• the length of synchronization transferred for each start event (FSLEN)
• the bit sense: most or lowest significant bit first (MSBF)
Additionally, the transmitter can be used to transfer synchronization and select the level driven on the TD pin while not in data transfer
operation. This is done respectively by the Frame Sync Data Enable (FSDEN) and by the Data Default Value (DATDEF) bits in
SSC_TFMR.
Figure 32-13: Transmit and Receive Frame Format in Edge/Pulse Start Modes
Note 1: Example of input on falling edge of TF/RF.
Table 32-2: Data Frame Registers
Transmitter Receiver Field Length Comment
SSC_TFMR SSC_RFMR DATLEN Up to 32 Size of word
SSC_TFMR SSC_RFMR DATNB Up to 16 Number of words transmitted in frame
SSC_TFMR SSC_RFMR MSBF Most significant bit first
SSC_TFMR SSC_RFMR FSLEN Up to 16 Size of Synchro data register
SSC_TFMR DATDEF 0 or 1 Data default value ended
SSC_TFMR FSDEN Enable send SSC_TSHR
SSC_TCMR SSC_RCMR PERIOD Up to 512 Frame size
SSC_TCMR SSC_RCMR STTDLY Up to 255 Size of transmit start delay
Sync Data
Default
STTDLY
Sync Data
Ignored
RD
Default
Data
DATLEN
Data
Data
Data
DATLEN
Data
Data
Default
Default
Ignored
Sync Data
Sync Data
FSLEN
TF/RF
(1)
Start
Start
From SSC_TSHR From SSC_THR
From SSC_THR
From SSC_THR
From SSC_THR
To SSC_RHR To SSC_RHRTo SSC_RSHR
TD
(If FSDEN = 0)
TD
(If FSDEN = 1)
DATNB
PERIOD
FromDATDEF
FromDATDEF
From DATDEF
From DATDEF