/SPI RX
while (1) {
   //clears the status register
   IOWR_ALTERA_AVALON_SPI_STATUS(SPI_0_BASE, 0);
   //if new byte arrived via SPI
   if ((IORD_ALTERA_AVALON_SPI_STATUS(SPI_0_BASE) &              ALTERA_AVALON_SPI_STATUS_RRDY_MSK) == 1){
   //read the byte and print it to screen
   printf("%x\n", (IORD_ALTERA_AVALON_SPI_RXDATA(SPI_0_BASE) & 0x0FF));
   }
}

为什么一直在查询状态寄存器，接受不了数据，心片TLC2543，频率1MHZ。NIOS处理器，STAITIX开发板