LPC1850 / Touch-TFT / SPIFI Flash, Assessment

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by kai.becker on Tue Feb 10 07:39:40 MST 2015
Hi all,

this is my first post in this forum. I hope I don´t break any forum rules, by
asking this without first thoroughly checking if a similar question has
been posted before.
I have done a search, but I haven´t found something comparable.

We want to develop a control unit for our devices. The control
unit should consist of a 4.3'' 16bit TFT Display with a
resisitve touch screeen.
Resisitve touch, because of the costs and because of the
fact, that our devices are always close to water.

So I´m looking for an assessment from people who have experience
using the LPC1850 processor with the following or similar peripherals.

LPC1850 @180MHz
parallel 512KB SRAM (no SDRAM)
Quad SPI Flash (Spansion S25FL164K, 108 MHz)
RGB 16bit TFT with 480x272 pixels
resistive touchscreen
UART communication every few seconds with 38400Baud.

My question is:
Does anyone "know", if the above configuration
will be responsive enough, so that a user will not see spurious
or even contious "lags" when using the control unit?

I mean is the Quad SPI Flash and Cortex-M3 fast enough
to satisfyingly solve this task?
The resisitve touch must also be tightly polled, because
a slider functionality should be realized.

We´re also thinking if it is better to use cheaper and bigger
SDRAM and to load the code from SPIFI Flash to RAM to
retrive a faster execution speed.

We have a done similar configuration with a
"computer on module" solution. The module had a
ARM9 (Toshiba TMPA900 @192MHz)
parallel NAND Flash
parallel SDRAM
and we connected a RGB 16bit TFT with 480x272 pixels (no touch)

This was fast enough for the control unit, but I think the ARM9
is considerably stronger than the Cortex-M3.
Also the code was loaded from Flash into SDRAM and
executed from SDRAM.

I would be very thankful if someone could post a plausible
assessment to the mentioned configuration.

Many many thanks in advantage to everyone who takes the
time to read my post.

Best regards