CC 7U: how to use the SPI mode

Hi there,

I’m trying to connect a serial device to a 7U - so the 7U shall act as SPI master. If’ve been reading the NS7520 manual and have been checking the internet for samples, but since the UNC20 forum is closed, its hard to find anything.

I followed the instructions in the manual, how to set up the serial port and then transmit a 16 bit word, using interrupt mode or DMA mode - but nothing happens on my GPIO pins.

I’m using the FS-Forth basboard where the PortA pins are accessible on the wire-wrap field. A programmed GPIO access works nice, the UART-serial-mode works also, but I cannot get the SPI mode transmitting anything.

Can anyone point me in the right direction, or perhaps provide some lines of a working example ? thanks in advance.

What I don’t fully understand is, what exactly triggers the transmission. I’m writing data to the transmitter fifo - does this trigger the SPI master to transmit the data, or is there any command bit, that needs to be set ?