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Altera_Forum's avatar
Altera_Forum
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13 years ago

Creating a bidirectional bus

I want to connect a USB chip (FT245R) to a CPLD. To do that I need a bidirectional 8-bit bus. I thought I could declare the pins to be bidirectional and with a mux, read to or write from the pins as ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

I rewrote my code as:

output [7:0] USBBUS;

wire [7:0] USBBUS;

reg [7:0] outbus;

wire [7:0] inbus;

always @(negedge clk) begin

if ((TXE == 0)) begin

USBBUS <= outbus;

end

else if ((RXF == 0)) begin

inbus <= USBBUS;

end

else begin

USBBUS <= 8'hz;

end

end

Now my error is: error (10137): verilog hdl procedural assignment error at testusb.v(344): object "usbbus" on left-hand side of assignment must have a variable data type

Any suggestions?