Lpc2000

--- In lpc2000@yahoogroups.com, "Ed Schlunder" <zilym@y...> wrote:
>
> I'm a little confused at what speeds can SD/MMC cards be accessed
> using SPI on the LPC2103. Normal SD/MMC cards support max 25MHz for SD
> and 20MHz for MMC.
> 

SPI is a low performance compatibility mode for MMC/SD cards, so it
hardly seems reasonable to expect it's performance to equal the native
mode performance, does it?  To achieve the full performance
capabilities of SD/MMC requires a dedicated controller in the
microcomputer, and the more general purpose SPI interface is not that
controller. The speeds that can be reached by SPI do seem to enable a
rather large number of useful MMC/SD applications though!

-- Dave