Jach Fong 
Hi! Everyone,
I had bought a Micro2440DK recently. I setup the required utilities
and everything goes fine. Now I try to figure out how fast the S3C2440A can
do on its GPIO. I write a small test program and download/run it through
DNW. The 2440DK was boot on NOR and I download it through the Supervivi's
'd' command.
Below is the subroutine to output a high-low (or low-high) pulse:
-------------
MyTest
LSL r2,r0,#5
MOV r1,#0x56000000
STR r2,[r1,#0x14]
;output to GPIOB
MVN r2,r2
STR r2,[r1,#0x14]
MVN r2,r2
STR r2,[r1,#0x14]
BX LR
--------------
But the result is terrible. The pulse width is 100ns! I had checked
that at this time the FCLK=405MHz, HCLK=FCLK/4 and PCLK=HCLK/2 and it's
already the limit of S3C2440A can have.
Please can someone tell me that if there are someway to improve the
speed? Or it is just the best I can get?
Best Regards,
Jach