Lpc2000

Hi Sutton

If you haven't done so yet, I think that it is time to reach for your 
oscilloscope. Perhaps the RAM is never responding at all because it is 
not being addressed properly (Its inbuilt address and bus 
configuration address).
To be sure that you are not being deceved, look at the SDA line during 
the 9th clock cycle sent from the master to see whether the slave (the 
RAM) is actually pulling it low and thus responding or not.
If it's not responding you will have to cure this first - although in 
this case I would also expect one of the following status in the 
interrupt after sending the address:
    case (0x48):                      // the slave address was sent 
but no ack was received (RX)
    case (0x20):                      // the slave address was sent 
but no ack was received (TX)

Cheers

Mark Butcher
www.mjbc.ch


--- In lpc2000@yahoogroups.com, "Sutton Mehaffey" <sutton@...> wrote:
>
> I haven't totally gotten my I2C (LPC2148) to work with my RAMTRON
> serial RAM yet.  All the status' look good on both writing and 
reading
> to RAM, but still get 0xA1 after I write a 0x77.  
> 
> However, I noticed that even if I have no power on my RAM and no SDA
> and SCK lines connected, all the status' are exactly the same and the
> data is still 0xA1.  It seems as though if the RAM weren't responding
> at all, you shouldn't get valid codes.  And, I have my ACKs turned 
on!
>  Any ideas?
> 
> Sutton
>