Hi,
I need to configure a system in a ML403 to make work the USB host
(CYPRESS CYC67300) toguether with the SystemAce core in my Linux 2.6.23
( secretlab ) . By now I have everything succesfully running without the
USB so I tried to follow the Xilinx Xapp925. Unfortunately, when looking
into the BSS there is no use of SystemAce. In fact, when if I try to use
the wizard to build a system from scratch, it argues that the Cypress
controller and the SystemAce cannot be used at the same time since they
share some resources. When looking more deeply into the files in
Xapp925, I have seen they include a simple IP core (glue logic) for some
pin multiplexing, but they don't make use of it.
The code itself is ( inside pcores/misc_logic_0_1.00.a/:
(...)
always @(posedge clk)
usb_ce_d1 <= usb_ce;
// USB and SysAce Mux Logic
assign usb_data_i = {sace_usb_d_I, 16'b0};
assign sysace_mpd_i = sace_usb_d_I;
assign sace_usb_a = (usb_ce | usb_ce_d1)?
{4'b0,usb_addr[28:29],1'b0} : sysace_mpa;
assign sace_usb_d_O = (usb_ce | usb_ce_d1)? usb_data_o[0:15] :
sysace_mpd_o;
assign sace_usb_d_T = (usb_ce | usb_ce_d1)? usb_data_t[0:15] :
sysace_mpd_t;
assign sace_usb_oen = (usb_ce_d1)? usb_rdn : sysace_mpoe;
assign sace_usb_wen = (usb_ce & usb_ce_d1)? usb_wrn : sysace_mpwe;
(...)
My questions are:
1. Will I be able to have both of them working in the same system?
2. Will the Linux drivers be able to cope with this "muxing"?
3. Will I have a penalty in performance if I use it?
I think this a very interesting question which I could not find any info
neither in this list or internet, but I suppose there must be many
people in the siltation of needing both USB and SystemACE to work together.
Thank you very much in advance,
/A
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