`include "../include/tune.v"
module zports(
input clk, // z80 clock
input fclk, // global FPGA clock
input rst_n, // system reset
input [7:0] din,
output reg [7:0] dout,
output dataout,
input [15:0] a,
input iorq_n,
input mreq_n,
input m1_n,
input rd_n,
input wr_n,
output reg porthit, // when internal port hit occurs, this is 1, else 0; used for iorq1_n iorq2_n on zxbus
output reg [15:0] ideout,
input [15:0] idein,
output idedataout, // IDE must IN data from IDE device when idedataout=0, else it OUTs
output [2:0] ide_a,
output ide_cs0_n,
output ide_cs1_n,
output ide_rd_n,
output ide_wr_n,
input [4:0] keyout,
output reg [2:0] border,
output reg beep,
output reg dos,
output ay_bdir,
output ay_bc1,
output [7:0] p7ffd,
output [7:0] peff7,
input [1:0] rstrom,
output vg_cs_n,
input vg_intrq,vg_drq, // from vg93 module - drq + irq read
output vg_wrFF, // write strobe of #FF port
output reg sdcs_n,
output sd_start,
output [7:0] sd_datain,
input [7:0] sd_dataout
);
reg rstsync1,rstsync2;
localparam PORTFE = 8'hFE;
localparam PORTF7 = 8'hF7;
localparam NIDE10 = 8'h10;
localparam NIDE11 = 8'h11;
localparam NIDE30 = 8'h30;
localparam NIDE50 = 8'h50;
localparam NIDE70 = 8'h70;
localparam NIDE90 = 8'h90;
localparam NIDEB0 = 8'hB0;
localparam NIDED0 = 8'hD0;
localparam NIDEF0 = 8'hF0;
localparam NIDEC8 = 8'hC8;
localparam PORTFD = 8'hFD;
localparam VGCOM = 8'h1F;
localparam VGTRK = 8'h3F;
localparam VGSEC = 8'h5F;
localparam VGDAT = 8'h7F;
localparam VGSYS = 8'hFF;
localparam KJOY = 8'h1F;
localparam KMOUSE = 8'hDF;
localparam SDCFG = 8'h77;
localparam SDDAT = 8'h57;
reg external_port;
reg port_wr;
reg port_rd;
reg iowr_reg;
reg iord_reg;
wire [7:0] loa;
wire portfe_wr;
wire ideout_hi_wr;
wire idein_lo_rd;
reg [7:0] idehiin;
reg ide_ports; // ide ports selected
reg pre_bc1,pre_bdir;
assign loa=a[7:0];
always @*
begin
if( (loa==PORTFE) || (loa==PORTFD) || (loa==PORTF7) || (loa==NIDE10) || (loa==NIDE11) || (loa==NIDE30) ||
(loa==NIDE50) || (loa==NIDE70) || (loa==NIDE90) || (loa==NIDEB0) || (loa==NIDED0) || (loa==NIDEF0) ||
(loa==NIDEC8) ||
( (loa==VGCOM)&&dos ) || ( (loa==VGTRK)&&dos ) || ( (loa==VGSEC)&&dos ) || ( (loa==VGDAT)&&dos ) ||
( (loa==VGSYS)&&dos ) || ( (loa==KJOY)&&(!dos) ) ||
(loa==KMOUSE) || (loa==SDCFG) || (loa==SDDAT) )
porthit = 1'b1;
else
porthit = 1'b0;
end
always @*
begin
if( ((loa==PORTFD) && (a[15:14]==2'b11)) || // 0xFFFD ports
(( (loa==VGCOM)&&dos ) || ( (loa==VGTRK)&&dos ) || ( (loa==VGSEC)&&dos ) || ( (loa==VGDAT)&&dos )) ) // vg93 ports
external_port = 1'b1;
else
external_port = 1'b0;
end
assign dataout = porthit & (~iorq_n) & (~rd_n) & (~external_port);
always @(posedge clk)
begin
iowr_reg <= ~(iorq_n | wr_n);
iord_reg <= ~(iorq_n | rd_n);
if( (!iowr_reg) && (!iorq_n) && (!wr_n) )
port_wr <= 1'b1;
else
port_wr <= 1'b0;
if( (!iord_reg) && (!iorq_n) && (!rd_n) )
port_rd <= 1'b1;
else
port_rd <= 1'b0;
end
// dout data
always @*
begin
case( loa )
PORTFE:
dout = { 1'b1, 1'b0/*tape_in*/, 1'b0, keyout };
NIDE10,NIDE30,NIDE50,NIDE70,NIDE90,NIDEB0,NIDED0,NIDEF0,NIDEC8:
dout = idein[7:0];
NIDE11:
dout = idehiin;
//PORTFD:
VGSYS:
dout = { vg_intrq, vg_drq, 6'b111111 };
KJOY:
dout = 8'h00;
KMOUSE:
dout = 8'hFF;
SDCFG:
dout = 8'h00; // always SD inserted, SD is on R/W mode // FIXME!FIXME!FIXME!FIXME!FIXME!
SDDAT:
dout = sd_dataout;
default:
dout = 8'hFF;
endcase
end
assign portfe_wr = ( (loa==PORTFE) && port_wr);
assign portfd_wr = ( (loa==PORTFD) && port_wr);
assign portf7_wr = ( (loa==PORTF7) && port_wr);
assign ideout_hi_wr = ( (loa==NIDE11) && port_wr);
assign idein_lo_rd = ( (loa==NIDE10) && port_rd);
assign vg_wrFF = ( ( (loa==VGSYS)&&dos ) && port_wr);
//port FE beep/border bit
always @(posedge clk)
begin
if( portfe_wr )
begin
beep <= din[4];
border <= din[2:0];
end
end
// IDE ports
always @*
ideout[7:0] = din;
always @(posedge clk)
begin
if( ideout_hi_wr )
ideout[15:8] <= din;
if( idein_lo_rd )
idehiin <= idein[15:8];
end
always @*
case( loa )
NIDE10,NIDE30,NIDE50,NIDE70,NIDE90,NIDEB0,NIDED0,NIDEF0,NIDEC8: ide_ports = 1'b1;
default: ide_ports = 1'b0;
endcase
assign ide_a = a[7:5];
// trying to fix old WD drives...
// assign ide_cs0_n = iorq_n | (rd_n&wr_n) | (~ide_ports) | (~(loa!=NIDEC8));
// assign ide_cs1_n = iorq_n | (rd_n&wr_n) | (~ide_ports) | (~(loa==NIDEC8));
assign ide_cs0_n = (~ide_ports) | (~(loa!=NIDEC8));
assign ide_cs1_n = (~ide_ports) | (~(loa==NIDEC8));
// fix ends...
assign ide_rd_n = iorq_n | rd_n | (~ide_ports);
assign ide_wr_n = iorq_n | wr_n | (~ide_ports);
assign idedataout = ide_rd_n;
// AY control
always @*
begin
pre_bc1 = 1'b0;
pre_bdir = 1'b0;
if( loa==PORTFD )
begin
if( a[15:14]==2'b11 )
begin
pre_bc1=1'b1;
pre_bdir=1'b1;
end
else if( a[15:14]==2'b10 )
begin
pre_bc1=1'b0;
pre_bdir=1'b1;
end
end
end
assign ay_bc1 = pre_bc1 & (~iorq_n) & ((~rd_n)|(~wr_n));
assign ay_bdir = pre_bdir & (~iorq_n) & (~wr_n);
// 7FFD port
reg [7:0] p7ffd_int,peff7_int;
reg p7ffd_rom_int;
wire block7ffd;
wire block1m;
always @(posedge clk, negedge rst_n)
begin
if( !rst_n )
p7ffd_int <= 7'h00;
else if( (a[15]==1'b0) && portfd_wr && (!block7ffd) )
p7ffd_int <= din; // 2..0 - page, 3 - screen, 4 - rom, 5 - block48k, 6..7 -
end
always @(posedge clk)
begin
if( rstsync2 )
p7ffd_rom_int <= rstrom[0];
else if( (a[15]==1'b0) && portfd_wr && (!block7ffd) )
p7ffd_rom_int <= din[4];
end
assign block7ffd=p7ffd_int[5] & block1m;
// EFF7 port
always @(posedge clk, negedge rst_n)
begin
if( !rst_n )
peff7_int <= 8'h00;
else if( (a[15:8]==8'hEF) && portf7_wr && (!block1m) )
peff7_int <= din; // 4 - turbooff, 0 - p16c on, 2 - block1meg
end
assign block1m = peff7_int[2];
assign p7ffd = block7ffd ? { 8'b00010000 } : { (block1m ? 3'b0 : p7ffd_int[7:5]),p7ffd_rom_int,p7ffd_int[3:0]};
// video modes + turbo are always modifiable. page0 ram is being blocked off
assign peff7 = block1m ? { 2'b00, peff7_int[5], peff7_int[4], 3'b000, peff7_int[0] } : peff7_int;
// VG93 control
assign vg_cs_n = (~dos) | iorq_n | (rd_n & wr_n) | ( ~((loa==VGCOM)|(loa==VGTRK)|(loa==VGSEC)|(loa==VGDAT)) );
// dos on-off
always @(posedge clk)
begin
if( rstsync2 )
dos <= ~rstrom[1];
else if( (!mreq_n) && (!m1_n) )
begin
if( (a[15:8]==8'h3D) && p7ffd[4] )
dos <= 1'b1;
else if( a[15:14]!=2'b00 )
dos <= 1'b0;
end
end
// reset rom selection
always @(posedge clk)
begin
rstsync1<=~rst_n;
rstsync2<=rstsync1;
end
// SD card (z-controlâ••r compatible)
wire sdcfg_wr,sddat_wr,sddat_rd;
assign sdcfg_wr = ( (loa==SDCFG) && port_wr);
assign sddat_wr = ( (loa==SDDAT) && port_wr);
assign sddat_rd = ( (loa==SDDAT) && port_rd);
// SDCFG write - sdcs_n control
always @(posedge clk, negedge rst_n)
begin
if( !rst_n )
sdcs_n <= 1'b1;
else // posedge clk
if( sdcfg_wr )
sdcs_n <= din[1];
end
// start signal for SPI module with resyncing to fclk
reg sd_start_toggle;
reg [2:0] sd_stgl;
// Z80 clock
always @(posedge clk)
if( sddat_wr || sddat_rd )
sd_start_toggle <= ~sd_start_toggle;
// FPGA clock
always @(posedge fclk)
sd_stgl[2:0] <= { sd_stgl[1:0], sd_start_toggle };
assign sd_start = ( sd_stgl[1] != sd_stgl[2] );
// data for SPI module
assign sd_datain = wr_n ? 8'hFF : din;
endmodule