adis16209 : switch/change command delay

Recently, I have been doing testing for adis16209 sensor. I came across a strange problem when running this piece of code:

 write_spi(ROT_OUT);  
 //wait until we receive rot_out_value from SPI  
 uart_write(rot_out_value);  
 write_spi(YINCL_OUT);  
 //wait until we receive yincl_out_value from SPI  
 uart_write(yincl_out_value);  

The sensor returns false values for ROT_OUT and YINCL_OUT commands. I started to dig into the problem and came to a conclusion that if we want to change the command (For example from ROT_OUT to YINCL_OUT), we must do like this :

 //switch to ROT_OUT command  
 write_spi(ROT_OUT);  
 //small delay  
 delay_us(40);  
 write_spi(ROT_OUT);  
 //wait until we receive rot_out_value from SPI  
 uart_write(rot_out_value);  
 //switch to YINCL_OUT command  
 write_spi(YINCL_OUT);  
 //small delay  
 delay_us(40);  
 write_spi(YINCL_OUT);  
 //wait until we receive yincl_out_value from SPI  
 uart_write(yincl_out_value);