Does SPI from NIOS II work?

Hello to anyone!!!
I've made some NIOS design with SPI and wrote small source code
....
 while(1) {
  usleep(10);
  alt_avalon_spi_command(SD_BASE, 0, 
                         6, write_data,
                         1, read_data,
                         flags); 
  }
....

but when I saw SCLK on Proto2 by oscilloscope, the SCLK's pin was "0" always,
SS_n was changing, MOSI was "0" and MISO was changing too (it's very strange).
I checked pin assignment and there is OK.

Maybe someone knowns what kind of problem I had there?

Thx.

Vladimir,

I seem to recall a colleague of mine mentioning something about a similar
issue.  I can check with him and get back to you, unless you already have
a solution...

Cheers,

- imaslacker