Lpc2000

On Sun, Nov 27, 2005 at 12:11:14AM +0100, Bertrik Sikken wrote:
> It turns out that, contrary to what I expected, the WRITE_MULTIPLE_BLOCK
> command is hardly any faster than the WRITE_BLOCK command.

It helps if you use the pre-erase command as well, but in your case
I doubt this has any impact.

> The WRITE_MULTIPLE_BLOCK command was configured to write 256 sectors
> of 512 bytes (128 kB). I measured the time by looking at my wristwatch.

> read            13 s
> write single    14 s
> write multiple  13 s

These results are remarkably slow. I have not used an LPC to drive an SD
card, but I have an application that reads/writes an SD card with an
8051 based chip (8051F320) using an SPI clock of 12.5MHz, and I can achieve
around 600 KB/sec read and write speed. Your figures are about 2 orders
of magnitude slower, which suggests there is something drastically wrong
with your code.

Clyde