Lpc2000

--- In lpc2000@yahoogroups.com, "drb5599" <dbutler@c...> wrote:
> Hello All,
> I have been using the SPI interface on a LPC2131 with good success 
so 
> far.  Now, I am trying to interface an LCD controller (HT1621) and 
> found a strange issue.  The LCD must have it's data written 12 bits
> at 
> a time.  So I configured the SPI control register to operate in 
this 
> mode.
> 
> S0SPCR      =   0x0C24;
> 
> which sets 
> bit#2: The SPI controller sends and receives the number of bis 
> selected by bits 11:8
> bit#5: Yes, I am using the LPC as a master
> bits#11:10: Selects 12 bits per transfer
> 
> However, when I step thru my code, and look at the S0SPCR register,
> it 
> is written with a 0x0424!!!!!!!!!!!!!
> For some reason bit 11 does not get written?  Consequently, this is
> an 
> undefined state for the register and it goes off into the wild 
blue 
> yonder and never stops sending out clock pulses.
> 
> I am able to stop the program and manually change the register 
> contents and I get the expected 12-bits shifted out.
> 
> Anybody ever experience this??  Is there a work around?
> 
> Also I am new to LCD's never programmed one before, the format of 
the 
> data looks really strange.  If anybody knows some good tricks for 
> interfacing an LCD with a serial interface, I would be grateful. 
> But, 
> for now I am really stuck with the problem at hand.
> 
> Thanks,
> Dave B.

Hi,

Use 8 bit plus 8 bit with one nibble NA, just keep CS active for two 
8-bit writes.
You have to control CS line for LCD from port pin anyhow.
Another way is to do bit banging (plenty of examples for that around)

good luck