// ZX-Evo Base Configuration (c) NedoPC 2008,2009,2010,2011,2012,2013,2014
//
// manages ZX-bus IORQ-IORQGE stuff and free bus content
/*
This file is part of ZX-Evo Base Configuration firmware.
ZX-Evo Base Configuration firmware is free software:
you can redistribute it and/or modify it under the terms of
the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
ZX-Evo Base Configuration firmware is distributed in the hope that
it will be useful, but WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with ZX-Evo Base Configuration firmware.
If not, see <http://www.gnu.org/licenses/>.
*/
`include "../include/tune.v"
module zbus(
input iorq_n,
input rd_n,
input wr_n,
input m1_n,
output iorq1_n,
output iorq2_n,
input iorqge1,
input iorqge2,
input porthit,
output drive_ff
);
assign iorq1_n = iorq_n | porthit;
assign iorq2_n = iorq1_n | iorqge1;
assign drive_ff = ( (~(iorq2_n|iorqge2)) & (~rd_n) ) | (~(m1_n|iorq_n));
endmodule