Do you have a question? Post it now! No Registration Necessary
Threaded View
Subject
posted on August 16, 2006, 7:35 am
Reply
Save
Print
Does anyone here understand how block addressing addressing works on SD
(secure digital) cards? I have a card that is FAT16.... and I can
initialized the card with my HC11, and can read 512 byte blocks of data
from it... however I can't understand how the addresses I'm using work.
It seems that no addresses will work untill address 0x200.... then only
multiples of 0x200 will work after that. This makes some sense I
guess, as 0x200 is 512 in decimal... so I guess I'm addressing blocks
of 512 bytes? But the confusion comes in when I try to look at my SD
card in HEX on my computer... the offsets don't seem to match up and
I'm unable to figure out how to get to a certain offset in the card
from the HC11. For instance, I know that a text file is stored
starting at 0x6A00 .
Anyone have some hints for me on this? I've never done any programming
with FAT's so maybe it's something universal to that and not specific
to SD cards.
Re: SD Addressing
Nevermind, I was looking at the card as a logical disk on my computer,
which makes 0x00 the start address of the logical drive, and not the
physical disk... I found a hex editor, WinHex that let's you look at
it as a pysical disk as well.
Take a look at this discussion for some really good information
-->http://forum.microchip.com/tm.aspx?m58%980&mpage13%
Site Timeline
- » SDCC model large problem
- — Next thread in » Microcontroller Discussions
-
- » "Stupid" question with PIC
- — Previous thread in » Microcontroller Discussions
-
- » iPhone SUPER 80% discounts
- — Newest thread in » Microcontroller Discussions
-
- » OPC and OPC UA
- — The site's Newest Thread. Posted in » Electronics Design
-
- » Regolatore velocita' ventilatore da soffitto
- — The site's Last Updated Thread. Posted in » Electronics Hobby (Italian)
-
XML Sitemap