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Message
From: antti at openchip.org<antti@o...>
Date: Thu Oct 21 07:28:23 CEST 2004
Subject: [oc] Secure Digital Memory Card Controller...
----- Original Message -----
From: pranesh prakash<pmdvlsi@y...>
To:
Date: Thu Oct 21 07:02:41 CEST 2004
Subject: [oc] Secure Digital Memory Card Controller...
> Sir,
> I've to implement the SD memory host within a XILINX COOLRUNNER II
> 2c128 device.
> I need to implement the
> a. command path unit.
> b. datapath unit
> c. control unit
> d. Card detect unit.
>
> Now I ve a problem. 2c128 has only 128 macrocells. i.e., 128 flip
> flpos.
> CRC logic itself takes (16*4) in datapath unit and (7*1) in
> command path unit. apart from this I need to implement
> Command/Response register.
> and moreover the control State machine needs some logic.
> How can I ensure It would fit in ONE COOLRUNNER II 2c128 by
> reducing some of its features. Its actually a project from XILINX.
> Please help.
there is no magic reduction possible, if you need SD card support
in 4 bit mode, you need 64 flipflops for that what is half the C128
I have made a MMC card application that fits into total 21 Coolrunner
PLD cells some info is at http://www.openchip.org/bootx
SD card is a little bit more complicated, also if you need to support
both MMC and SD cards you need some additional logic as some
commands are different.
given my experience with the MMC card I would say it is possible
to implement a minimalist SD card host in C128, but you would need
almost full 100% utilization of the chip. And you can only support
8 bit command/datapath.
hm.. you said it "from Xilinx" so they want to have this design?
Xilinx promised they will have SD Host IP core, but they never
made it public, so I assume they want it now :)
antti
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