Sport interface supports a variety of serial data communication protocols. Key features and capability of SPORT interface are
SCLK = 120MHz
SPORT_TCLKDIV = 0 to 65535
Other allowable values : 60MHz, 30MHz, 20MHz, 12MHz, 10MHz, 7.5MHz, 6MHz
NOTE : The value of Transmit Frame Sync Frequency is a function of the clock frequency of the transmit clock. SPORT_TFSDIV is the number of serial clock cycles between frame sync assertions.
SPORT_TFSDIV must be greater than the serial word length -1. This ensures that the the frame sync is deasserted prior to reassertion for the the framed word. Therefore depending on the word size chosen for data transmission and the clock frequency selected the Frame Sync freqency will vary. Taking a 60MHz TSCLK and a serial wordlenght of 32. The minimum and maximum SPORT TFS are calculated as follows
The Receive Clock freqency and the Receive Frame Rates available can be calculated similarily to the TSCLK and the TFS rates
SCLK = 120MHz
SPORT_RCLKDIV = 0 to 65535
RSCLK Max = 60MHz, RSCLK MIN ≈ 915.52Hz
|Pin Blackfin Name||Pin 120 Pin Connector Name||Description|
|DTxPRI||SPORT_DT0||Transmit Data Primary|
|DTxSEC||SPORT_DT1||Transmit Data Secondary|
|TFSx||SPORT_TFS||Transmit Frame Sync|
|DRxPRI||SPORT_DR0||Receive Data Primary|
|DRxSEC||SPORT_DR1||Receive Data Secondary|
|TRSx||SPORT_RFS||Receive Frame Sync|
Table 1: SPORT Pin Assignments
There are two transmit and two receive channels in the SPORT interface. By default the primary transmit and receive channels, DT0 and DR0, are enabled and the secondary transmit and receive channels, DT1 and DR1, are disabled. To enable the secondary transmit and receive channels, set the secEnable property in the SPORT object to true and wire the second transmit and receive lines to DT1 and DR1. The max clock frequency which can be used in this case is now halved, so 30MHz SPORT TSCLK and RSCLK. The data sent down to the SDP should be interleaved, the every second location containing data for DT0 and DT1 respectively. Below is a timing example showing the transmit clock, frame sync and data lines with SecEnable set to true.
To achieve the example below the array transmitted over the SPORT interface is
Similarly data read from the SDP SPORT Interface in secEnable mode must be de-interleaved in the top level application to separate the data into data from DR0 and DR1.
An Early Frame Sync Signal will be active for one clock pulse, and then become deactivate. Once the signal has been deactivated, valid data will be available.
A Late Frame Sync Signal frames the valid data, so is active for the length of time that valid data is available and is deactivated once the word to be transmitted or received has been fully sent.
There are two SPORT Controllers on the Blackfin BF527 and these are exposed through the two connectors on the SDP-B.
SPORT0 is on Connector A of the SDP, SPORT1 is on Connector B of the SDP.
The SPORT Interface Pins are 3.3V tolerant only.