// ZXiznet project
// (c) NedoPC 2018
//
// testbench
`timescale 1ns/100ps
//// CPU at 14MHz
`define HALF_CPU_PERIOD (35.7)
// CPU at 7MHz
//`define HALF_CPU_PERIOD (70)
// filter clock
`define HALF_FCLK_PERIOD (10.4)
module tb;
reg rst_n;
reg clk;
reg fclk;
tri1 iorq_n,
mreq_n,
rd_n,
wr_n;
tri1 int_n;
wire csrom_n;
wire iorqge,
blkrom;
wire [15:0] a;
wire [ 7:0] d;
tri [ 7:0] #1 bd;
wire brd_n, bwr_n;
reg [7:0] tmp;
wire [9:0] w5300_addr;
wire w5300_rst_n;
wire w5300_cs_n;
wire w5300_int_n;
wire sl811_rst_n;
wire sl811_a0;
wire sl811_cs_n;
wire sl811_ms_n;
wire sl811_intrq;
reg usb_power;
reg [1:0] where_rom;
// filter clock
initial
begin
fclk = 1'b1;
forever #`HALF_FCLK_PERIOD fclk = ~fclk;
end
initial
begin
clk = 1'b1;
forever #`HALF_CPU_PERIOD clk = ~clk;
end
initial
begin
rst_n = 1'b0;
repeat(3) @(posedge clk);
rst_n <= 1'b1;
end
initial
begin
where_rom = 2'b00;
usb_power = 1'b0;
end
top DUT
(
.fclk(fclk),
.za(a),
.zd(d),
.ziorq_n(iorq_n),
.zmreq_n(mreq_n),
.zrd_n(rd_n),
.zwr_n(wr_n),
.zcsrom_n(csrom_n),
.ziorqge(iorqge),
.zblkrom(blkrom),
.zrst_n(rst_n),
.zint_n(int_n),
.bd(bd),
.bwr_n(bwr_n),
.brd_n(brd_n),
.w5300_rst_n(w5300_rst_n),
.w5300_addr (w5300_addr ),
.w5300_cs_n (w5300_cs_n ),
.w5300_int_n(w5300_int_n),
.sl811_rst_n(sl811_rst_n),
.sl811_intrq(sl811_intrq),
.sl811_ms_n (sl811_ms_n ),
.sl811_cs_n (sl811_cs_n ),
.sl811_a0 (sl811_a0 ),
.usb_power(usb_power)
);
ssz80 z
(
.clk (clk ),
.rst_n(rst_n),
.iorq_n(iorq_n),
.mreq_n(mreq_n),
.rd_n (rd_n ),
.wr_n (wr_n ),
.a(a),
.d(d)
);
w5300 w
(
.rst_n(w5300_rst_n),
.addr (w5300_addr ),
.cs_n (w5300_cs_n ),
.rd_n (brd_n ),
.wr_n (bwr_n ),
.int_n(w5300_int_n),
.d(bd)
);
sl811 s
(
.rst_n(sl811_rst_n),
.a0 (sl811_a0 ),
.cs_n (sl811_cs_n ),
.wr_n (bwr_n ),
.rd_n (brd_n ),
.ms (~sl811_ms_n),
.intrq(sl811_intrq),
.d(bd)
);
// csrom gen
assign csrom_n = !(a[15:14]==where_rom[1:0]);
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////
/// here start tests
reg [15:0] rstint_port = 16'h83_AB;
reg [15:0] w5300_port = 16'h82_AB;
reg [15:0] sl811_port = 16'h81_AB;
reg [15:0] sl_addr = 16'h80_AB;
reg [15:0] sl_data = 16'h7F_AB;
initial
begin : tests
reg [7:0] tmp;
reg [7:0] tmp2;
wait(rst_n===1'b1);
repeat(10) @(posedge clk);
test_pwon_resets();
test_pwon_ints();
forever // repeat(10000)
begin
case( $random%6 )
0: check_sl811_access();
1: check_w5300_mem_access();
2: check_w5300_port_access();
3: test_resets();
4: check_sl811_port();
5: test_ints();
endcase
end
$display("all tests passed!");
$stop;
end
task wait_end_access();
reg a;
a = 1'b0;
wait( brd_n==1'b1 && bwr_n==1'b1 );
a <= 1'b1;
wait(a==1'b1);
endtask
// translates memory address to w5300 address in accordance with specs
function [9:0] mk_w5300_addr( input [13:0] mem_addr );
if( mem_addr<14'h2000 )
begin
mk_w5300_addr = mem_addr[9:0];
end
else if( mem_addr<14'h3000 )
begin
mk_w5300_addr[9] = 1'b1;
mk_w5300_addr[8:6] = mem_addr[11:9];
mk_w5300_addr[5:1] = 5'b10111;
mk_w5300_addr[0] = mem_addr[0];
end
else // if( mem_addr<14'h4000 )
begin
mk_w5300_addr[9] = 1'b1;
mk_w5300_addr[8:6] = mem_addr[11:9];
mk_w5300_addr[5:1] = 5'b11000;
mk_w5300_addr[0] = mem_addr[0];
end
endfunction
task check_w5300_port_access();
reg [7:0] tmp,rddata,wrdata;
reg [9:0] waddr;
reg a0_inv;
reg [15:0] port;
a0_inv = $random>>31;
waddr = $random>>22;
z.iowr(w5300_port,{waddr[9:7],1'b1,a0_inv,3'd0});
z.iord(w5300_port,tmp);
if( tmp!=={waddr[9:7],1'b1,a0_inv,3'd0} )
begin
$display("can't set w5300 port!");
$stop;
end
// make access port address
port = sl_data;
port[14:8] = waddr[6:0];
w.init_access(); // clear access_* to X
if( $random>>31 )
begin
wrdata = $random>>24;
z.iowr(port,wrdata);
wait_end_access();
if( w.get_addr()!==(waddr^a0_inv) ||
w.get_rnw()!==1'b0 ||
w.get_wr_data()!==wrdata )
begin
$display("w5300 port write failed!");
$stop;
end
end
else
begin
rddata = $random>>24;
w.set_rd_data(rddata);
z.iord(port,tmp);
@(negedge clk);
if( w.get_addr()!==(waddr^a0_inv) ||
w.get_rnw()!==1'b1 ||
tmp!==rddata )
begin
$display("w5300 port read failed!");
$stop;
end
end
endtask
task check_w5300_mem_access;
reg [7:0] tmp,rddata,wrdata;
reg [15:0] memaddr;
reg [ 9:0] waddr;
reg [1:0] rom;
reg a0_inv;
reg sub_ena;
rom = $random>>30;
a0_inv = $random>>31;
sub_ena= $random>>31;
z.iowr(w5300_port,{4'd0,a0_inv,sub_ena,rom});
z.iord(w5300_port,tmp);
if( tmp!=={4'd0,a0_inv,sub_ena,rom} )
begin
$display("can't set w5300 port!");
$stop;
end
if( $random>>31 )
where_rom = rom;
else
begin
where_rom = $random>>30;
while( where_rom==rom )
where_rom = $random>>30;
end
w.init_access(); // clear access_* to X
memaddr = $random>>18;
memaddr[15:14] = where_rom;
if( $random>>31 )
begin
repeat(10)
begin
wrdata = $random>>24;
z.memwr(memaddr,wrdata);
wait_end_access();
if( where_rom==rom && sub_ena )
begin
if( w.get_addr()!==(mk_w5300_addr(memaddr[13:0])^a0_inv) ||
w.get_rnw()!==1'b0 ||
w.get_wr_data()!==wrdata )
begin
$display("w5300 write failed!");
$stop;
end
end
else
begin
if( w.get_addr()!=={10{1'bX}} || w.get_rnw()!==1'bX || w.get_wr_data()!=={8{1'bX}} )
begin
$display("write succeeded with wrong ROM mapping!");
$stop;
end
end
end
end
else
begin
rddata = $random>>24;
w.set_rd_data(rddata);
z.memrd(memaddr,tmp);
@(negedge clk);
if( where_rom==rom && sub_ena )
begin
if( w.get_addr()!==(mk_w5300_addr(memaddr[13:0])^a0_inv) ||
w.get_rnw()!==1'b1 ||
tmp!==rddata )
begin
$display("w5300 read failed!");
$stop;
end
end
else
begin
if( w.get_addr()!=={10{1'bX}} || w.get_rnw()!==1'bX )
begin
$display("read succeeded with wrong ROM mapping!");
$stop;
end
end
end
endtask
task check_sl811_access;
reg [7:0] tmp, rddata, wrdata;
reg [15:0] rdport;
// turn off w5300 port access
z.iord(w5300_port,tmp);
if( tmp[4]!==1'b0 )
begin
tmp[4]=1'b0;
z.iowr(w5300_port,tmp);
end
// check address reg
wrdata=$random>>24;
z.iowr(sl_addr,wrdata);
wait_end_access();
if( s.get_rnw()!==1'b0 || s.get_addr()!==1'b0 || s.get_wr_data()!==wrdata )
begin
$display("sl811 address write failed!");
$stop;
end
//
rddata=$random>>24;
s.set_rd_data(rddata);
z.iord(sl_addr,tmp);
@(negedge clk);
if( s.get_rnw()!==1'b1 || s.get_addr()!==1'b0 || tmp!==rddata )
begin
$display("sl811 address read failed!");
$stop;
end
// check data reg
rdport=sl_data;
rdport[14:8]=$random>>25;
wrdata=$random>>24;
z.iowr(rdport,wrdata);
wait_end_access();
if( s.get_rnw()!==1'b0 || s.get_addr()!==1'b1 || s.get_wr_data()!==wrdata )
begin
$display("sl811 data write failed!");
$stop;
end
//
rddata=$random>>24;
s.set_rd_data(rddata);
z.iord(rdport,tmp);
@(negedge clk);
if( s.get_rnw()!==1'b1 || s.get_addr()!==1'b1 || tmp!==rddata )
begin
$display("sl811 data read failed!");
$stop;
end
endtask
task check_sl811_port;
reg [7:0] tmp;
reg ms;
ms=$random>>31;
z.iowr(sl811_port,ms);
wait_end_access();
@(posedge clk);
if( (rst_n===1'b1 && s.get_ms()!==ms ) ||
(rst_n===1'b0 && s.get_ms()!==1'b1 ) )
begin
$display("sl811_ms_n behaves wrong!");
$stop;
end
usb_power <= $random>>31;
@(posedge clk);
z.iord(sl811_port,tmp);
if( tmp[1]!==usb_power )
begin
$display("can't sense usb_power!");
$stop;
end
endtask
task test_pwon_ints;
reg [7:0] tmp;
// check ints
z.iord(rstint_port,tmp);
if( tmp[1:0]!==2'b00 )
begin
$display("int requests after reset!");
$stop;
end
if( tmp[3:2]!==2'b00 )
begin
$display("ints enabled after reset!");
$stop;
end
if( tmp[7]!==1'b0 )
begin
$display("internal int is on after reset!");
$stop;
end
if( tmp[6]!==1'b0 )
begin
$display("ext.int assertion enabled after reset!");
$stop;
end
if( int_n!==1'b1 )
begin
$display("ext.int asserted after reset!");
$stop;
end
endtask
task test_ints;
reg [7:0] tmp;
reg [1:0] ints,intena;
reg eintena;
ints = $random>>30;
intena = $random>>30;
eintena = $random>>31;
s.set_intrq(ints[1]);
w.set_int_n(~ints[0]);
@(posedge clk);
z.iord(rstint_port,tmp);
tmp[3:2]=intena;
tmp[6]=eintena;
z.iowr(rstint_port,tmp);
z.iord(rstint_port,tmp);
if( tmp[1]!==ints[1] || tmp[0]!==ints[0] )
begin
$display("wrong int signals states!");
$stop;
end
if( ( (ints&intena) && tmp[7]!==1'b1) ||
( !(ints&intena) && tmp[7]!==1'b0) )
begin
$display("wrong internal int state!");
$stop;
end
if( tmp[6]!==eintena )
begin
$display("wrong eintena state!");
$stop;
end
if( (eintena && (ints&intena)) ? (int_n!==1'b0) : (int_n!==1'b1) )
begin
$display("wrong int_n forming!");
$stop;
end
endtask
task test_resets;
reg [7:0] tmp;
reg [1:0] resets;
resets = $random>>30;
// read-modify-write reset register
z.iord(rstint_port,tmp);
tmp[5:4] = resets[1:0];
z.iowr(rstint_port,tmp);
if( s.get_rst_n() !== resets[1] )
begin
$display("no control of sl811 reset!");
$stop;
end
if( w.get_rst_n() !== resets[0] )
begin
$display("no control of w5300 reset!");
$stop;
end
endtask
task test_pwon_resets;
reg [7:0] tmp;
// test resets state after reset
if( w.get_rst_n() !== 1'b0 )
begin
$display("w5300 hasn't rst_n=0 after reset!");
$stop;
end
//
if( s.get_rst_n() !== 1'b0 )
begin
$display("sl811 hasn't rst_n=0 after reset!");
$stop;
end
// read reset register and check it
z.iord(rstint_port,tmp);
if( tmp[5:4]!==2'b00 )
begin
$display("reset bits in #83AB not 0 after reset!");
$stop;
end
endtask
// time marks
always
begin : timemarks
int ms;
ms = ($time/1000000);
#1000000.0;
$display("time mark: %d ms",ms);
end
endmodule