NAND connected with address lines based example

Marcus Mikolaiczyk m.mikolaiczyk at
Thu Mar 31 04:07:47 EST 2005

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?

Kind Regards


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