Due toggle SCK after completed SPI-transfer

Hi, i try to run an TLC5940 on my Due via SPI for some hardware resaons. (not via USART or something else).

What i need and still have not found is a way to toggle the SCK-signal after every completed SPI-transmission.

Once, SPI is initialized, i do not have access to A.27 (SCK) to do an extra pulse on that pin.

Is there a chance to switch between SPI and OUTPUT-Mode and back ?

Can anybody help?

Try a dummy SPI.transfer call. It works with the SD card problem.