Hello all.
I am going to be honest from the start and inform you that I am posting this
thread to assist with a final year project for my degree.
I am building an audio spectrum analyser using a c6711 DSK development board.
Currently working on the processing of the audio. However I want to be able to
display the data on an LCD display 128*64 graphic unit.
I have read some of the previous posts on this, but need some assistance with
answering a few questions. I have also read the PDF SPRA 542 on EMIF
connections
1. I know in previous posts that it has been said the LCD may be too slow for
the processor, would this cause problems with the processor, or would it cause
delays in the response, therefore the display not running in real-time?
2. I was thinking of using a parallel display using the EMIF connections, is
this ok to do? The other option was to use a serial connection using the MCBSP.
However I also want to use an audio daughter card PCM3003, so i think that this
would not be possible?
3. Previous posts talk of using a tri state buffer when driving the LCD. The
drawing show that there is already one in circuit, so therefore would not need
one?
3. As I am using the PCM3003 daughter card, can I still also access the other
daughter connection (the PCM3003 cover both connections but only uses one, but
can still fit the prototype connector in- just)
I have already got the correct connector to gain access to the daughter
connection.
Thanks for your help in advance. Look forward to reading any replies!
duncan mills
_____________________________________
C6711 DSK - LCD display
Started by ●February 10, 2011
Reply by ●February 10, 20112011-02-10
Hello Duncan,
Thanks for doing your homework and posting specific questions. See
comments below.
mikedunn
On 2/10/2011 4:10 AM, m...@btinternet.com wrote:
>
> Hello all.
>
> I am going to be honest from the start and inform you that I am
> posting this thread to assist with a final year project for my degree.
>
> I am building an audio spectrum analyser using a c6711 DSK development
> board. Currently working on the processing of the audio. However I
> want to be able to display the data on an LCD display 128*64 graphic
> unit.
>
> I have read some of the previous posts on this, but need some
> assistance with answering a few questions. I have also read the PDF
> SPRA 542 on EMIF connections
>
> 1. I know in previous posts that it has been said the LCD may be too
> slow for the processor, would this cause problems with the processor,
> or would it cause delays in the response, therefore the display not
> running in real-time?
>
If I remember correctly, the issue was technically "the update speed of
the LCD interface" was in question. You can compute the interface speed
requirements.
Update frequency: at least 25 updates per sec is ideal. 15-20 would
possibly work - depending on the screen update method. The key is to be
able to send 1 screen of data within the desired update period.
> 2. I was thinking of using a parallel display using the EMIF
> connections, is this ok to do?
>
There are no problems using the EMIF - with a proper design.
>
> The other option was to use a serial connection using the MCBSP.
> However I also want to use an audio daughter card PCM3003, so i think
> that this would not be possible?
>
The 6711DSK has 2 McBSP ports - you can reroute the onboard audio McBSP
port with a jumper.
> 3. Previous posts talk of using a tri state buffer when driving the
> LCD. The drawing show that there is already one in circuit, so
> therefore would not need one?
>
There are buffers on all [or most] daughtercard signals. You should not
need a tristate buffer unless there is some 'funky reason' that the
interface requires it.
> 3. As I am using the PCM3003 daughter card, can I still also access
> the other daughter connection (the PCM3003 cover both connections but
> only uses one, but can still fit the prototype connector in- just)
> I have already got the correct connector to gain access to the
> daughter connection.
>
I have seen as many as 3 daughtercards stacked on top of each other.
> Thanks for your help in advance. Look forward to reading any replies!
>
> duncan mills
Thanks for doing your homework and posting specific questions. See
comments below.
mikedunn
On 2/10/2011 4:10 AM, m...@btinternet.com wrote:
>
> Hello all.
>
> I am going to be honest from the start and inform you that I am
> posting this thread to assist with a final year project for my degree.
>
> I am building an audio spectrum analyser using a c6711 DSK development
> board. Currently working on the processing of the audio. However I
> want to be able to display the data on an LCD display 128*64 graphic
> unit.
>
> I have read some of the previous posts on this, but need some
> assistance with answering a few questions. I have also read the PDF
> SPRA 542 on EMIF connections
>
> 1. I know in previous posts that it has been said the LCD may be too
> slow for the processor, would this cause problems with the processor,
> or would it cause delays in the response, therefore the display not
> running in real-time?
>
If I remember correctly, the issue was technically "the update speed of
the LCD interface" was in question. You can compute the interface speed
requirements.
Update frequency: at least 25 updates per sec is ideal. 15-20 would
possibly work - depending on the screen update method. The key is to be
able to send 1 screen of data within the desired update period.
> 2. I was thinking of using a parallel display using the EMIF
> connections, is this ok to do?
>
There are no problems using the EMIF - with a proper design.
>
> The other option was to use a serial connection using the MCBSP.
> However I also want to use an audio daughter card PCM3003, so i think
> that this would not be possible?
>
The 6711DSK has 2 McBSP ports - you can reroute the onboard audio McBSP
port with a jumper.
> 3. Previous posts talk of using a tri state buffer when driving the
> LCD. The drawing show that there is already one in circuit, so
> therefore would not need one?
>
There are buffers on all [or most] daughtercard signals. You should not
need a tristate buffer unless there is some 'funky reason' that the
interface requires it.
> 3. As I am using the PCM3003 daughter card, can I still also access
> the other daughter connection (the PCM3003 cover both connections but
> only uses one, but can still fit the prototype connector in- just)
> I have already got the correct connector to gain access to the
> daughter connection.
>
I have seen as many as 3 daughtercards stacked on top of each other.
> Thanks for your help in advance. Look forward to reading any replies!
>
> duncan mills
Reply by ●February 10, 20112011-02-10
Mills,
How fast do you want to update the LCD display?
You probably realize that the human eye is only so fast, about 16 frames per
second is fast enough for video motion (with slight flicker) and 32 frames per
second makes for some very smooth video, especially if the LCD display has some
'persistence'.
--How is the LCD accessed? Serial, parallel, SIO, direct bus connection?
--Does the LCD have frame buffers? 1, 2, more?
--Does the LCD have a retrace time with a outgoing signal to indicate when the
retrace is active? Works well for eliminating 'black' momentary events when
updating the visible display.
--For most LCD displays, a graphic image is needed, though some LCDs have the
ability to display ascii numbers without the need for any graphics. What are
the capabilities of the LCD you are planning to use?
--Does the LCD display have multiple memory images stored, so updating the
display is a sequence of ... write new images via line by line pixels to a non
visible memory image area. Then during 'retrace', swap the memory image area
that is being displayed.
Or perhaps the LCD needs lots of input lines and only displays what ever the
line drivers currently have on their outputs.
The fun is always in the details.
R. Williams
---------- Original Message -----------
From: m...@btinternet.com
To: c...
Sent: Thu, 10 Feb 2011 05:10:22 -0500
Subject: [c6x] C6711 DSK - LCD display
> Hello all.
>
> I am going to be honest from the start and inform you that I am
> posting this thread to assist with a final year project for my degree.
>
> I am building an audio spectrum analyser using a c6711 DSK development
> board. Currently working on the processing of the audio. However I
> want to be able to display the data on an LCD display 128*64 graphic
> unit.
>
> I have read some of the previous posts on this, but need some
> assistance with answering a few questions. I have also read the PDF
> SPRA 542 on EMIF connections
>
> 1. I know in previous posts that it has been said the LCD may be too
> slow for the processor, would this cause problems with the processor,
> or would it cause delays in the response, therefore the display not
> running in real-time?
>
> 2. I was thinking of using a parallel display using the EMIF
> connections, is this ok to do? The other option was to use a serial
> connection using the MCBSP. However I also want to use an audio
> daughter card PCM3003, so i think that this would not be possible?
>
> 3. Previous posts talk of using a tri state buffer when driving the
> LCD. The drawing show that there is already one in circuit, so
> therefore would not need one?
>
> 3. As I am using the PCM3003 daughter card, can I still also access
> the other daughter connection (the PCM3003 cover both connections but
> only uses one, but can still fit the prototype connector in- just) I
> have already got the correct connector to gain access to the daughter connection.
>
> Thanks for your help in advance. Look forward to reading any replies!
>
> duncan mills
------- End of Original Message -------
_____________________________________
How fast do you want to update the LCD display?
You probably realize that the human eye is only so fast, about 16 frames per
second is fast enough for video motion (with slight flicker) and 32 frames per
second makes for some very smooth video, especially if the LCD display has some
'persistence'.
--How is the LCD accessed? Serial, parallel, SIO, direct bus connection?
--Does the LCD have frame buffers? 1, 2, more?
--Does the LCD have a retrace time with a outgoing signal to indicate when the
retrace is active? Works well for eliminating 'black' momentary events when
updating the visible display.
--For most LCD displays, a graphic image is needed, though some LCDs have the
ability to display ascii numbers without the need for any graphics. What are
the capabilities of the LCD you are planning to use?
--Does the LCD display have multiple memory images stored, so updating the
display is a sequence of ... write new images via line by line pixels to a non
visible memory image area. Then during 'retrace', swap the memory image area
that is being displayed.
Or perhaps the LCD needs lots of input lines and only displays what ever the
line drivers currently have on their outputs.
The fun is always in the details.
R. Williams
---------- Original Message -----------
From: m...@btinternet.com
To: c...
Sent: Thu, 10 Feb 2011 05:10:22 -0500
Subject: [c6x] C6711 DSK - LCD display
> Hello all.
>
> I am going to be honest from the start and inform you that I am
> posting this thread to assist with a final year project for my degree.
>
> I am building an audio spectrum analyser using a c6711 DSK development
> board. Currently working on the processing of the audio. However I
> want to be able to display the data on an LCD display 128*64 graphic
> unit.
>
> I have read some of the previous posts on this, but need some
> assistance with answering a few questions. I have also read the PDF
> SPRA 542 on EMIF connections
>
> 1. I know in previous posts that it has been said the LCD may be too
> slow for the processor, would this cause problems with the processor,
> or would it cause delays in the response, therefore the display not
> running in real-time?
>
> 2. I was thinking of using a parallel display using the EMIF
> connections, is this ok to do? The other option was to use a serial
> connection using the MCBSP. However I also want to use an audio
> daughter card PCM3003, so i think that this would not be possible?
>
> 3. Previous posts talk of using a tri state buffer when driving the
> LCD. The drawing show that there is already one in circuit, so
> therefore would not need one?
>
> 3. As I am using the PCM3003 daughter card, can I still also access
> the other daughter connection (the PCM3003 cover both connections but
> only uses one, but can still fit the prototype connector in- just) I
> have already got the correct connector to gain access to the daughter connection.
>
> Thanks for your help in advance. Look forward to reading any replies!
>
> duncan mills
------- End of Original Message -------
_____________________________________
