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// (c) NedoPC 2010
//
// wait generator for Z80
module zwait(
input wire rst_n,
input wire wait_start_gluclock,
input wire wait_end,
output reg [6:0] waits,
output wire wait_n,
output wire spiint_n
);
wire wait_off_n;
assign wait_off_n = (~wait_end) & rst_n;
always @(posedge wait_start_gluclock, negedge wait_off_n)
begin
if( !wait_off_n )
waits[0] <= 1'b0;
else if( wait_start_gluclock )
waits[0] <= 1'b1;
end
always @(posedge wait_end) // just dummy for future extensions
begin
waits[6:1] <= 6'd0;
end
assign spiint_n = ~|waits;
assign wait_n = spiint_n ? 1'bZ : 1'b0;
endmodule