?? sdr_sdram_tb.v
字號:
for(i = 1; i <= length-2; i = i + 1)
begin
#1000;
datain <= start_value + i;
@(posedge clk);
end
#1000;
datain <= start_value + i; // keep incrementing the data value
#1000;
cmd <= 3'b100; // issue a precharge/terminate command to terminate the page burst
@(posedge clk);
#1000;
datain <= start_value + i + 1; // increment the data one more
@(cmdack == 1) // Wait for the controller to ack the command
#2000;
cmd <= 3'b000; // Clear the command by issuing a NOP
dm <= 0;
#1000000;
cmd <= 3'b100; // issue a precharge command to close the page
@(posedge clk);
@(cmdack==1);
@(posedge clk);
#1000;
cmd <= 3'b000;
end
endtask
// page_read_burst(address, start_value, CL, RCD, length)
//
// This task performs a page read access of size length
// at SDRAM address to the SDRAM controller
//
// address : Address in SDRAM to start the burst access
// start_value : Starting value for the burst read sequence. The read burst task
// simply increments and compares the data values from the start_value.
// CL : CAS latency the sdram devices have been configured for.
// RCD : RCD value the controller has been configured for.
// length : burst length of the access
task page_read_burst;
input [`ASIZE-1 : 0] address;
input [`DSIZE-1 : 0] start_value;
input [1 : 0] CL;
input [1 : 0] RCD;
input [15 : 0] length;
integer i;
reg [`DSIZE-1 : 0] read_data;
begin
addr <= address;
cmd <= 3'b001; // issue a read command to the controller
@(cmdack == 1); // wait for the controller to ack
@(posedge clk);
#1000;
cmd <= 3'b000;
// NOP on the command input
for (i=1 ; i<=(CL+RCD+1); i=i+1) // Wait for activate and cas latency delays
@(posedge clk);
for(i = 1; i <= length; i = i + 1) // loop and collect the data
begin
@(posedge clk);
read_data <= dataout;
#2000;
if (i == (length-8)) cmd <= 3'b100; // Terminate the page burst
if (cmdack == 1) cmd<=3'b000; // end the precharge command once the controller has ack'd
if (read_data !== start_value + i - 1)
begin
$display("Read error at %h read %h expected %h", (addr+i-1), read_data, (start_value + i -1));
$stop;
end
end
end
endtask
// config(bl, cl, rc, pm, ref)
//
// This task cofigures the SDRAM devices and the controller
//
// bl : Burst length 1,2,4, or 8
// cl : Cas latency, 2 or 3
// rc : Ras to Cas delay.
// pm : page mode setting
// ref : refresh period setting
task config;
input [3 : 0] bl;
input [1 : 0] cl;
input [1 : 0] rc;
input pm;
input [15: 0] ref;
reg [`ASIZE-1 : 0] config_data;
begin
config_data <= 0;
@(posedge clk);
@(posedge clk);
@(posedge clk);
if (bl == 1)
config_data[2:0] <= 3'b000; // Set the Burst length portion of the mode data
else if (bl == 2)
config_data[2:0] <= 3'b001;
else if (bl == 4)
config_data[2:0] <= 3'b010;
else if (bl == 8)
config_data[2:0] <= 3'b011;
else if (bl == 0)
config_data[2:0] <= 3'b111; // full page burst configuration value for bl
config_data[6:4] <= cl;
// issue precharge before issuing load_mode
@(posedge clk);
cmd <= 3'b100;
@(cmdack == 1) // Wait for the controller to ack the command
#2000;
cmd <= 3'b000; // Clear the command by issuing a NOP
@(posedge clk);
#2000;
// load mode register
cmd <= 3'b101;
addr[15:0] <= config_data;
@(cmdack == 1) // Wait for the controller to ack the command
cmd <= 3'b000; // Clear the command by issuing a NOP
config_data <= 0;
config_data[15:0] <= ref;
@(posedge clk);
// load refresh counter
@(posedge clk);
addr[15:0] <= config_data;
cmd <= 3'b111;
@(cmdack == 1 ); // Wait for the controller to ack the command
#2000;
cmd <= 3'b000; // Clear the command by issuing a NOP
addr <= 0;
config_data <= 0;
config_data[1:0] <= cl; // load contorller reg1
config_data[3:2] <= rc;
config_data[8] <= pm;
config_data[12:9] <= bl;
@(posedge clk);
#2000;
addr[15:0] <= config_data;
cmd <= 3'b110;
@(cmdack == 1) // Wait for the controller to ack the command
#2000;
cmd <= 3'b000; // Clear the command by issuing a NOP
addr <= 0;
config_data <= 0;
end
endtask
initial begin
cmd = 0;
addr = 0;
ref_ack = 0;
dm <= 0;
#3000000;
$display("Testing page burst accesses");
config(0,3,3,1,1526);
#1000000;
$display("Writing a ramp value from 0-29 out to sdram at address 0x0");
page_write_burst(0, 0, 4'h0, 3, 30);
#1000000;
$display("Reading the ramp value from sdram at address 0x0");
page_read_burst(0,0,3,3,30);
#1000000;
$display("Testing data mask inputs");
config(8,3,3,0,1526);
#1000000;
$display("writing pattern 0,1,2,3,4,5,6,7 to sdram at address 0x0");
burst_write(0, 0, 4'b0, 3, 8);
$display("Reading and verifing the pattern 0,1,2,3,4,5,6,7 at sdram address 0x0");
burst_read(0, 0, 3, 3, 8);
$display("Writing pattern 0xfffffff0, 0xfffffff1, 0xfffffff2, 0xfffffff3, 0xfffffff4, 0xfffffff5, 0xfffffff6, 0xfffffff7");
$display("with DM set to 0xf");
burst_write(0, 32'hfffffff0, 4'b1111, 3, 8);
$display("Reading and verifing that the pattern at sdram address 0x0 is");
$display("still 0,1,2,3,4,5,6,7");
burst_read(0, 0, 3, 3, 8);
$display("End of data mask test");
bl = 1;
for (x = 1; x <=4; x = x + 1)
begin
for (y = 3; y <= 3; y = y + 1) // at 133mhz cl must be 3, if 100mhz cl can be 2
begin
for (z = 3; z <=3; z = z + 1) //at 133mhz rc must be 3, if 100mhz rc can be 2
begin
$display("configuring for bl = %d cl = %d rc = %d",bl,y,z);
config(bl, y, z, 0, 1526);
// perform 1024 burst writes to the first chip select, writing a ramp pattern
$display("Peforming burst write to first sdram bank");
test_data <= 0;
test_addr <= 0;
@(posedge clk);
@(posedge clk);
for (j = 0; j < `LOOP_LENGTH; j = j + 1)
begin
burst_write(test_addr, test_data, 4'h0, z, bl);
test_data <= test_data + bl;
test_addr <= test_addr + bl;
#50000;
end
// perform 1024 burst reads to the first chip select, verifing the ramp pattern
$display("Performing burst read, verify ramp values in first sdram bank");
test_data <= 0;
test_addr <= 0;
@(posedge clk);
@(posedge clk);
for (j = 0; j < `LOOP_LENGTH; j = j + 1)
begin
burst_read(test_addr, test_data, y, z, bl);
test_data <= test_data + bl;
test_addr <= test_addr + bl;
end
#500000;
// perform 1024 burst writes to the second chip select, writing a ramp pattern
$display("Peforming burst write to second sdram bank");
test_data <= 24'h400000;
test_addr <= 24'h400000;
@(posedge clk);
@(posedge clk);
for (j = 0; j < `LOOP_LENGTH; j = j + 1)
begin
burst_write(test_addr, test_data, 4'h0, z, bl);
test_data <= test_data + bl;
test_addr <= test_addr + bl;
@(posedge clk);
end
// perform 1024 burst reads to the second chip select, verifing the ramp pattern
$display("Performing burst read, verify ramp values in second sdram bank");
test_data <= 24'h400000;
test_addr <= 24'h400000;
@(posedge clk);
@(posedge clk);
for (j = 0; j < `LOOP_LENGTH; j = j + 1)
begin
burst_read(test_addr, test_data, y, z, bl);
test_data <= test_data + bl;
test_addr <= test_addr + bl;
end
#500000;
$display("Test complete");
end
end
bl = bl * 2;
$stop;
end
endmodule
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