LPC1347 GPIO - Pin Write for LCD

[lpcware]

Content originally posted in LPCWare by PsychedelicBreakfast on Sat Oct 27 06:08:10 MST 2012
I am migrating a design from a LPC1343 which drives a 800x480 RGB display. When I initially started programming the LPC1343 I noticed that writing to the display was rather slow. After some digging, I realised that enabling compiler optimisation and using pointers to access the MASKED DATA register is way faster than using GPIOSetValue declared in gpio.c. I was able to achieve speeds of upto 18 MHz in a simple loop.

With the above changes, I was able to write to the display very very quickly - I couldn't notice the screen filling with colour. It was fast enough that it seemed that the entire display changed colour at the same time.

I now have to move up to the LPC1347. As I understand, the 1347 has a significantly improved the GPIO block. From the UM, it seems that by using the byte PIN registers I can change individual pins without changing anything else. My concern is, how fast are these? Can I simply do the following:

while(1)
{
LPC_GPIO->B0[0] = 0xFF
LOC_GOIO->B0[0] = 0x00
}

and achieve fast write speeds?