All I want to do is be able to read data from a file and throw it out of either multiple UARTS, fast SPIs or 8 bit parallel, into an FPGA at rates of 1-4Mbytes/sec continuous (i.e. need enough extra speed & RAM buffering to cover any filesystem latency).
I've used the PIC24F parts with USB host and SD, which work fine as far as they go but the fundamental speed of the interface is a limiting factor. (as well as, at least in the case of SD, inefficient code, but this is fairly easy to tweak for a 2-3x efficiency gain)
Does any one know of any MCU that satisfies the following :
USB 2.0 high speed or SDHC port, and working free example code to read from a memory device, which can be compiled with a free or low-cost toolchain. (Ideally IAR EWB kickstart edition)
Not BGA, and readily available in small qty (10s). Onboard Phy would be nice.
Not under Linux - just power up & go. It will not be doing anything else - just reading a file and streaming it out so don't want the baggage and learning curve of an OS
NXP LPC1800 looks a possibility with their nxpUSBlib library but not clear if their USB library supports hi-speed. This post indicates that there are some major performance issues at the moment
http://www.lpcware.com/content/forum/mass-storage-readwrite-performance-lpc18xxAt least non-BGA packages appear to be becoming more available now.
Bare metal code on a RasPi may be an option if I can get the data out somehow - maybe parallel via IO pins - not looked in detail yet - does anyone know if there is a file system avaialabe yet for bare-metal users?
This looked promising but speed is limited by the slow interface to the host, and the 4MBytes/sec speeds claimed turn out to only be useful for card-card copying.
http://www.ghielectronics.com/catalog/product/340I think this is based on a ST ARM Cortex M3 chip.
If they had a way to, for example read USB and spit it out of the 4-bit SPI interface, under control of the UART port that could be ideal.
Something that can be got up & running easily with minimal learning curve is highest priority - parts cost not a major issue.
Just wondering if anyone else has looked into this before I start digging any further..