I'm new to arm programming, with books and examples found on the Internet I goota some of the microcontroler functions to work like: use of fic, irq, uart0, rtc, gp/io, lcd mod, a/d. I'm really lost now, i'm trying to communicate with the SD CARD to initially write a block and record a variable for example. And in a futher use a Fat32 filesystem. I'm using Yagarto compiler. I found some examples of mmc with fat chan library but don't work with my board, or i dont know how to initializate the card. Anyone can pass me more detalled informations about the use of SD CARD using the MCI protocol? Where can I start studing to complete this Task? Any information will help a lot.
John wrote: > I'm new to arm programming, with books and examples found on the > Internet I goota some of the microcontroler functions to work like: use > of fic, irq, uart0, rtc, gp/io, lcd mod, a/d. > I'm really lost now, i'm trying to communicate with the SD CARD to > initially write a block and record a variable for example. And in a > futher use a Fat32 filesystem. > > I'm using Yagarto compiler. > > I found some examples of mmc with fat chan library but don't work with > my board, or i dont know how to initializate the card. ChaN has an example with LPC23xx/24xx MCI support in is "sample-package" available from elm-chan (do not confuse this with my project from www.siwawi..., I just mixed code from various sources and wrote some glue-functions. ChaN created his own code from scratch and this one should be prefered). If it does not work with your board double-check the connections. Maybe there is FET to enable/disable the card's VCC. Try to build a prototype exactly like ChaN's schematic or at least try to find the differences. There is also example-code for the low-level-functions available from the NXP-site and from keil.com (mind the license). The efsl (beta RC xzy) also includes some MCI code. > Anyone can pass me more detalled informations about the use of SD CARD > using the MCI protocol? If the LPC's manual is not enough, search the technical library on arm.com. There is a document which describes the MCI-cell. Also a full SD and/or SDHC specification might be useful.
I do what you have suggested, starts to study the elm-chan project
example.
I got the circuit that he uses in a image that goes with the example
code.
Analising the only difference that i found in the circuit of my board is
that the MCI POWER pin in his board is changed to P0.10 as a GPIO pin.
In my board this pin is connect to MCI_POWER pin (P0.21).
The only reference that I found to pin P0.10 in the code is in mci.c:
#define SOCKPORT FIO0PIN1 /* Socket contact port */
#define SOCKINS 0x04 /* Card detect switch (bit2) */
#define SOCKWP 0 /* Write protect switch (none) */
What I understand is that the interruption change the stat analising
this pin to know if there is a card connected to the socket.
In my board, the same pin, is connected to P0.21, that should be:
#define SOCKPORT FIO0PIN2
#define SOCKINS 0x20
#define SOCKWP 0
but with this change still don't work, i got an error verifing if there
is a Card conected to the socket, returns 3 (STA_NOINIT|STA_NODISK).
The same value is returned if the card is or isn't on the board.
Sure there is not the correctly form to verify if there is a Card
connected to the board. How can I verify if there is a card connected to
a board to pass this state check?
I also tried to force the Stat variable to be 0 (all OK) to pass this
step of verification. The verification pass, identify the card as SDC
ver1 or SDC ver2 correctly (I tryed both), but in this part of mci.c
goto di_fail (error):
mci.c / inside disk_initialize function:
do { /* Wait while card is busy state (use ACMD41 or CMD1) */
/* This loop will take a time. Insert wai_tsk(1) here for multitask
envilonment. */
if (!Timer[0]) goto di_fail;
} while (!send_cmd(cmd, 0x00FF8000, 1, resp) || !(resp[0] &
0x80000000));
The response received goto a error.
Can anyone help-me to solve this or indicating where can I be missing?
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