Posted on July 26, 2005 at 12:31Original project started with RISE part, but have had to move to ST Vega.
The configuration needs the following
56Mb SDRAM memory, PCI bus to onboard components, (no sockets), Ethernet, USB, boot flash, two IDE, keyboard and mouse, (for development only). RS232 if easily available.
No floppy or soundcard.
Having looked at the application note it is not clear if I need all of the devices.
I have the following questions:
a) I was not aware of the ''local bus'' referred to by Rise, is it a PC standard or a proprietary bus? Is there a document detailing the actual bus transactions?
b) To get the keyboard and mouse do I have to select ISA bus and a SuperIO device, or is there a simpler method just using the local bus?
c) Does RS232 also have to come from a SuperIO device or else can it be sourced directly from the UART?
d) For their SDRAM memory interface they've used the Cypress 2309 with the PLL turned off so it is just a clock buffer. I would prefer to use the 2305, (its smaller), which has the PLL always on. Should I connect the CLKOUT of the 2305 to the MCLKI of the Vega, or will this cause the two PLL's to clash in which case should I just load the CLKOUT with a matching load and leave MCLKI unconnected?
e) I am using 4 off 64Mbit SDRAM arranged as 4x512x32. Therefore I only have 11 address bits and 2 bank bits. Should I connect MA[12:11] to the memory bank pins, or should I connect BA[1:0]?
e) TRST is listed as a pin, but does not have a pad number.
[ This message was edited by: Anna on 26-07-2005 16:27 ]
