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Line 12... |
// Creator: Dan Gisselquist, Ph.D.
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// Creator: Dan Gisselquist, Ph.D.
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// Gisselquist Technology, LLC
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// Gisselquist Technology, LLC
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//
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//
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////////////////////////////////////////////////////////////////////////////////
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////////////////////////////////////////////////////////////////////////////////
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//
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//
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// Copyright (C) 2015-2016, Gisselquist Technology, LLC
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// Copyright (C) 2015-2017, Gisselquist Technology, LLC
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//
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//
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// This program is free software (firmware): you can redistribute it and/or
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// This program is free software (firmware): you can redistribute it and/or
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// modify it under the terms of the GNU General Public License as published
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// modify it under the terms of the GNU General Public License as published
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// by the Free Software Foundation, either version 3 of the License, or (at
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// by the Free Software Foundation, either version 3 of the License, or (at
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// your option) any later version.
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// your option) any later version.
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| Line 25... |
Line 25... |
// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
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// ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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// for more details.
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// for more details.
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//
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//
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// You should have received a copy of the GNU General Public License along
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// You should have received a copy of the GNU General Public License along
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// with this program. (It's in the $(ROOT)/doc directory, run make with no
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// with this program. (It's in the $(ROOT)/doc directory. Run make with no
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// target there if the PDF file isn't present.) If not, see
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// target there if the PDF file isn't present.) If not, see
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// <http://www.gnu.org/licenses/> for a copy.
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// <http://www.gnu.org/licenses/> for a copy.
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//
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//
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// License: GPL, v3, as defined and found on www.gnu.org,
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// License: GPL, v3, as defined and found on www.gnu.org,
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// http://www.gnu.org/licenses/gpl.html
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// http://www.gnu.org/licenses/gpl.html
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Line 75... |
{ l_dstb_n, l_astb_n, l_write_n } <= { r_dstb_n, r_astb_n, r_write_n };
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{ l_dstb_n, l_astb_n, l_write_n } <= { r_dstb_n, r_astb_n, r_write_n };
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end
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end
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reg [7:0] addr;
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reg [7:0] addr;
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wire astb, dstb, w_write;
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wire astb, dstb, w_write;
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assign astb = (~r_astb_n)&&(l_astb_n);
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assign astb = (!r_astb_n)&&(l_astb_n);
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assign dstb = (~r_dstb_n)&&(l_dstb_n);
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assign dstb = (!r_dstb_n)&&(l_dstb_n);
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assign w_write= (~r_write_n);
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assign w_write= (!r_write_n);
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initial addr = 8'h00;
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initial addr = 8'h00;
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initial o_rx_stb = 1'b0;
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initial o_rx_stb = 1'b0;
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always @(posedge i_clk)
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always @(posedge i_clk)
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| Line 100... |
Line 100... |
// Much as I hate to use signals that have not been synchronized with a
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// Much as I hate to use signals that have not been synchronized with a
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// two clock transfer, this line needs to be brought low within 10ms
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// two clock transfer, this line needs to be brought low within 10ms
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// (less than one clock) of when the strobe lines are brought low, and
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// (less than one clock) of when the strobe lines are brought low, and
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// raised high again within 10 ms of when the strobe lines are raised
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// raised high again within 10 ms of when the strobe lines are raised
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// again.
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// again.
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assign o_wait = ((~i_dstb_n)||(~i_astb_n));
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assign o_wait = ((!i_dstb_n)||(!i_astb_n));
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// For one clock, following any read from address zero, we allow the
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// For one clock, following any read from address zero, we allow the
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// port to write one new byte into our interface. This works because
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// port to write one new byte into our interface. This works because
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// the interface will guarantee that the strobe signals are inactive
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// the interface will guarantee that the strobe signals are inactive
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// (high) for at least 40ns before attempting a new transaction.
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// (high) for at least 40ns before attempting a new transaction.
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