How to use

[Altera_Forum]

i m using alt_avalon_spi_command() now, and i did it according to Altera Embedded Peripherals Handbook chapter 7. I m looking using SPI to transfer some data to another board. And i can't figure out how to use this command line.  

 int alt_avalon_spi_command(alt_u32 base, alt_u32 slave,  alt_u32 write_length, const alt_u8* wdata, alt_u32 read_length,  alt_u8* read_data, alt_u32 flags)  1) Where can i find what value i should put for alt_u32 slave?  2) What value should i put for flag?  3) If i m going to just send the data, in MOSI mode, what value should i put for read_length and read_data? 4) do you have an example demostrating how to use this command ? I just can't get it to work on Nios II cyclone board.  how is i wrote the code   _______________________________________________________  /*   alt_u8 sending[16] = {  0x81, 0xCF, 0x92, 0x86, 0xCC, 0xA4, 0xA0, 0x8F, 0x80, 0x84,   0x88, 0xE0, 0xF2, 0xC2, 0xB0, 0xB8 };     alt_u8 receiving[16];  download= alt_avalon_spi_command(0x00800000,1,16, sending,16, receiving,1);  _______________________________________________________  and the output has no signal coming out. I can't figure out anything goes wrong.

[Altera_Forum]

--- Quote Start ---  originally posted by wei_chen0428@Mar 14 2006, 05:06 AM int alt_avalon_spi_command(alt_u32 base, alt_u32 slave,  alt_u32 write_length, const alt_u8* wdata,  alt_u32 read_length,  alt_u8* read_data, alt_u32 flags)  1) where can i find what value i should put for alt_u32 slave?  2) what value should i put for flag?  3) if i m going to just send the data, in mosi mode, what value should i put for read_length and read_data? 4) do you have an example demostrating how to use this command ?  <div align='right'><{post_snapback}> (index.php?act=findpost&pid=13399)  --- quote end ---    --- Quote End ---   May You see source code of "altera_avalon_spi.c" ? If you can do it you can find out function alt_avalon_spi_command. And see all information about this function and its variables. I recommend you read manual about SPI in SOPC builder

[Altera_Forum]

--- Quote Start ---  originally posted by wei_chen0428@Mar 14 2006, 05:06 AM int alt_avalon_spi_command(alt_u32 base, alt_u32 slave,  alt_u32 write_length, const alt_u8* wdata,  alt_u32 read_length,  alt_u8* read_data, alt_u32 flags)  1) where can i find what value i should put for alt_u32 slave?  2) what value should i put for flag?  3) if i m going to just send the data, in mosi mode, what value should i put for read_length and read_data? 4) do you have an example demostrating how to use this command ?  <div align='right'><{post_snapback}> (index.php?act=findpost&pid=13399)  --- quote end ---    --- Quote End ---    1. alt_u32 slave is the number of slave connected to your master, with the first one starting from "0", as pointed out in the documentation.  2. Flag = ALT_AVALON_SPI_COMMAND_MERGE, if you wish to use that function, else put 0.

[Altera_Forum]

--- Quote Start ---  [/b]  --- Quote End ---    1. alt_u32 slave is the number of slave connected to your master, with the first one starting from "0", as pointed out in the documentation.   So if I have 4 slaves connected to the SPI master, I should set slave =0x03? I think this argument is used to select which slave I want to write or read, e.g.: if I want to read or write slave 0, I should set slave = 0x00, correct?  Thanks.