Hi,
I have a project where I'm interfacing an LPC2148 to a UC1601s LCD
controller. I have set up the SPI interface to operate in 9 bit mode.
When I issue a "clearLCD" command ie I write 0 to all the display
memory locations I get randome pixels activated across the display. I
have obsereved the SPI interface with a logic analyser and I have seen
that random 1s appear in the bit stream.
Does anyone know what could be causing this?
Thanks in advance
Andrew
SPI comms to UC1601s
Started by ●August 4, 2008
Reply by ●August 4, 20082008-08-04
On Mon, 04 Aug 2008 08:47:59 -0000, you wrote:
>Hi,
>
>I have a project where I'm interfacing an LPC2148 to a UC1601s LCD
>controller. I have set up the SPI interface to operate in 9 bit mode.
>
>When I issue a "clearLCD" command ie I write 0 to all the display
>memory locations I get randome pixels activated across the display. I
>have obsereved the SPI interface with a logic analyser and I have seen
>that random 1s appear in the bit stream.
>
>Does anyone know what could be causing this?
>
>Thanks in advance
>
>Andrew
Check you are observing all the constraints on clock division ratio as shown in the UM - I've seen
the LPC213x SPI do odd things when running faster
don't know the 2148, but for example on the 2136/01, S0SPCCR must be even and >8
>
>
>Hi,
>
>I have a project where I'm interfacing an LPC2148 to a UC1601s LCD
>controller. I have set up the SPI interface to operate in 9 bit mode.
>
>When I issue a "clearLCD" command ie I write 0 to all the display
>memory locations I get randome pixels activated across the display. I
>have obsereved the SPI interface with a logic analyser and I have seen
>that random 1s appear in the bit stream.
>
>Does anyone know what could be causing this?
>
>Thanks in advance
>
>Andrew
Check you are observing all the constraints on clock division ratio as shown in the UM - I've seen
the LPC213x SPI do odd things when running faster
don't know the 2148, but for example on the 2136/01, S0SPCCR must be even and >8
>
>
Reply by ●August 4, 20082008-08-04
Thanks for the tip.
I have since found out that I hadn't set up the page address
coreectly and this was preventing the correct operation of the LCD.
Andrew
--- In l..., Mike Harrison wrote:
>
> On Mon, 04 Aug 2008 08:47:59 -0000, you wrote:
>
> >Hi,
> >
> >I have a project where I'm interfacing an LPC2148 to a UC1601s LCD
> >controller. I have set up the SPI interface to operate in 9 bit
mode.
> >
> >When I issue a "clearLCD" command ie I write 0 to all the display
> >memory locations I get randome pixels activated across the
display. I
> >have obsereved the SPI interface with a logic analyser and I have
seen
> >that random 1s appear in the bit stream.
> >
> >Does anyone know what could be causing this?
> >
> >Thanks in advance
> >
> >Andrew
>
> Check you are observing all the constraints on clock division
ratio as shown in the UM - I've seen
> the LPC213x SPI do odd things when running faster
> don't know the 2148, but for example on the 2136/01, S0SPCCR must
be even and >8
>
> >
> >
> >
> >
I have since found out that I hadn't set up the page address
coreectly and this was preventing the correct operation of the LCD.
Andrew
--- In l..., Mike Harrison wrote:
>
> On Mon, 04 Aug 2008 08:47:59 -0000, you wrote:
>
> >Hi,
> >
> >I have a project where I'm interfacing an LPC2148 to a UC1601s LCD
> >controller. I have set up the SPI interface to operate in 9 bit
mode.
> >
> >When I issue a "clearLCD" command ie I write 0 to all the display
> >memory locations I get randome pixels activated across the
display. I
> >have obsereved the SPI interface with a logic analyser and I have
seen
> >that random 1s appear in the bit stream.
> >
> >Does anyone know what could be causing this?
> >
> >Thanks in advance
> >
> >Andrew
>
> Check you are observing all the constraints on clock division
ratio as shown in the UM - I've seen
> the LPC213x SPI do odd things when running faster
> don't know the 2148, but for example on the 2136/01, S0SPCCR must
be even and >8
>
> >
> >
> >
> >
