Re: NAND connected with address lines based example

[William J Beksi <wjbeksi@setabox.com>]

Hi Marcus,

Marcus Mikolaiczyk wrote:
> Dear list users,
> 
> I got a system where a Samsung NAND ist connect  via Adresslines (A0 ->
> CLE, A1 -> ALE) using a chipselect from the processor. I looked through
> the guide "MTD NAND Driver Programming Interface" and the sources to
> adapt an existing driver. Now I stuck with a problem concerning the
> board_hwcontrol function.
> It's alwas there that CLE/ALE have a set and a clear command. But in my
> setup the CLE/ALE setting is made through the access of the
> addresslines. See the table:
> 
>         A1(ALE)   A0(CLE)  Beispieladresse    Funktion
> -------------------------------------------------------------------------------
> 1         0         0       0xA8000000        read/write access on mem
> 2         0         1       0xA8000001        Command
> 3         1         0       0xA8000002        Addresssetting
> 4         1         1       0xA8000003        not valid
> 
> The base is A8000000 for example.
> Now writing a Byte to 0xA8000001 (a NAND command) automatically sets ALE
> =0 and CLE=1
> Writing the addressparts is done through writing the 1st databyte Col1
> to address 0xA8000002 and so on.
> Concerning now the function board_hwcontrol there is the
> ...
> switch(cmd) {
> 		case NAND_CTL_SETCLE: /* Write to addr 0xA8000001 */;break;
> 		case NAND_CTL_CLRCLE: /* do nothing */;break;
> 		case NAND_CTL_SETALE: /* Write to addr 0xA8000002 */;break;
> 		case NAND_CTL_CLRALE: /* do nothing */;break;
> }
> ...
> Am I right when these commands have to be empty in this case?
> Where do I tell the system to use the address 0xA8000001 for commands
> and 0xA8000002 for addresses?

You can write your hardware control function like this:

switch(cmd) {
	case NAND_CTL_SETCLE: this->IO_ADDR_W = io_base_addr+1; break;
	case NAND_CTL_CLRCLE: this->IO_ADDR_W = io_base_addr; break;
	case NAND_CTL_SETALE: this->IO_ADDR_W = io_base_addr+2; break;	
	case NAND_CTL_CLRALE: this->IO_ADDR_W = io_base_addr; break;
}

Where io_base_addr = A8000000, your base address.

Hope this helps.
-- 
William J Beksi                          <wjbeksi@users.sourceforge.net>
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