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//including, without limitation, that your use is for the sole purpose
//of programming logic devices manufactured by Altera and sold by Altera
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//agreement for further details.
// synthesis translate_off
`timescale 1ns / 1ps
// synthesis translate_on
// turn off superfluous verilog processor warnings
// altera message_level Level1
// altera message_off 10034 10035 10036 10037 10230 10240 10030
module sdram_input_efifo_module (
// inputs:
clk,
rd,
reset_n,
wr,
wr_data,
// outputs:
almost_empty,
almost_full,
empty,
full,
rd_data
)
;
output almost_empty;
output almost_full;
output empty;
output full;
output [ 40: 0] rd_data;
input clk;
input rd;
input reset_n;
input wr;
input [ 40: 0] wr_data;
wire almost_empty;
wire almost_full;
wire empty;
reg [ 1: 0] entries;
reg [ 40: 0] entry_0;
reg [ 40: 0] entry_1;
wire full;
reg rd_address;
reg [ 40: 0] rd_data;
wire [ 1: 0] rdwr;
reg wr_address;
assign rdwr = {rd, wr};
assign full = entries == 2;
assign almost_full = entries >= 1;
assign empty = entries == 0;
assign almost_empty = entries <= 1;
always @(entry_0 or entry_1 or rd_address)
begin
case (rd_address) // synthesis parallel_case full_case
1'd0: begin
rd_data <= entry_0;
end // 1'd0
1'd1: begin
rd_data <= entry_1;
end // 1'd1
default: begin
end // default
endcase // rd_address
end
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
begin
wr_address <= 0;
rd_address <= 0;
entries <= 0;
end
else
case (rdwr) // synthesis parallel_case full_case
2'd1: begin
// Write data
if (!full)
begin
entries <= entries + 1;
wr_address <= (wr_address == 1) ? 0 : (wr_address + 1);
end
end // 2'd1
2'd2: begin
// Read data
if (!empty)
begin
entries <= entries - 1;
rd_address <= (rd_address == 1) ? 0 : (rd_address + 1);
end
end // 2'd2
2'd3: begin
wr_address <= (wr_address == 1) ? 0 : (wr_address + 1);
rd_address <= (rd_address == 1) ? 0 : (rd_address + 1);
end // 2'd3
default: begin
end // default
endcase // rdwr
end
always @(posedge clk)
begin
//Write data
if (wr & !full)
case (wr_address) // synthesis parallel_case full_case
1'd0: begin
entry_0 <= wr_data;
end // 1'd0
1'd1: begin
entry_1 <= wr_data;
end // 1'd1
default: begin
end // default
endcase // wr_address
end
endmodule
// turn off superfluous verilog processor warnings
// altera message_level Level1
// altera message_off 10034 10035 10036 10037 10230 10240 10030
module sdram (
// inputs:
az_addr,
az_be_n,
az_cs,
az_data,
az_rd_n,
az_wr_n,
clk,
reset_n,
// outputs:
za_data,
za_valid,
za_waitrequest,
zs_addr,
zs_ba,
zs_cas_n,
zs_cke,
zs_cs_n,
zs_dq,
zs_dqm,
zs_ras_n,
zs_we_n
)
;
output [ 15: 0] za_data;
output za_valid;
output za_waitrequest;
output [ 11: 0] zs_addr;
output [ 1: 0] zs_ba;
output zs_cas_n;
output zs_cke;
output zs_cs_n;
inout [ 15: 0] zs_dq;
output [ 1: 0] zs_dqm;
output zs_ras_n;
output zs_we_n;
input [ 21: 0] az_addr;
input [ 1: 0] az_be_n;
input az_cs;
input [ 15: 0] az_data;
input az_rd_n;
input az_wr_n;
input clk;
input reset_n;
wire [ 23: 0] CODE;
reg ack_refresh_request;
reg [ 21: 0] active_addr;
wire [ 1: 0] active_bank;
reg active_cs_n;
reg [ 15: 0] active_data;
reg [ 1: 0] active_dqm;
reg active_rnw;
wire almost_empty;
wire almost_full;
wire bank_match;
wire [ 7: 0] cas_addr;
wire clk_en;
wire [ 3: 0] cmd_all;
wire [ 2: 0] cmd_code;
wire cs_n;
wire csn_decode;
wire csn_match;
wire [ 21: 0] f_addr;
wire [ 1: 0] f_bank;
wire f_cs_n;
wire [ 15: 0] f_data;
wire [ 1: 0] f_dqm;
wire f_empty;
reg f_pop;
wire f_rnw;
wire f_select;
wire [ 40: 0] fifo_read_data;
reg [ 11: 0] i_addr;
reg [ 3: 0] i_cmd;
reg [ 2: 0] i_count;
reg [ 2: 0] i_next;
reg [ 2: 0] i_refs;
reg [ 2: 0] i_state;
reg init_done;
reg [ 11: 0] m_addr /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_REGISTER=ON" */;
reg [ 1: 0] m_bank /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_REGISTER=ON" */;
reg [ 3: 0] m_cmd /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_REGISTER=ON" */;
reg [ 2: 0] m_count;
reg [ 15: 0] m_data /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_REGISTER=ON ; FAST_OUTPUT_ENABLE_REGISTER=ON" */;
reg [ 1: 0] m_dqm /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_REGISTER=ON" */;
reg [ 8: 0] m_next;
reg [ 8: 0] m_state;
reg oe /* synthesis ALTERA_ATTRIBUTE = "FAST_OUTPUT_ENABLE_REGISTER=ON" */;
wire pending;
wire rd_strobe;
reg [ 2: 0] rd_valid;
reg [ 12: 0] refresh_counter;
reg refresh_request;
wire rnw_match;
wire row_match;
wire [ 23: 0] txt_code;
reg za_cannotrefresh;
reg [ 15: 0] za_data /* synthesis ALTERA_ATTRIBUTE = "FAST_INPUT_REGISTER=ON" */;
reg za_valid;
wire za_waitrequest;
wire [ 11: 0] zs_addr;
wire [ 1: 0] zs_ba;
wire zs_cas_n;
wire zs_cke;
wire zs_cs_n;
wire [ 15: 0] zs_dq;
wire [ 1: 0] zs_dqm;
wire zs_ras_n;
wire zs_we_n;
assign clk_en = 1;
//s1, which is an e_avalon_slave
assign {zs_cs_n, zs_ras_n, zs_cas_n, zs_we_n} = m_cmd;
assign zs_addr = m_addr;
assign zs_cke = clk_en;
assign zs_dq = oe?m_data:{16{1'bz}};
assign zs_dqm = m_dqm;
assign zs_ba = m_bank;
assign f_select = f_pop & pending;
assign f_cs_n = 1'b0;
assign cs_n = f_select ? f_cs_n : active_cs_n;
assign csn_decode = cs_n;
assign {f_rnw, f_addr, f_dqm, f_data} = fifo_read_data;
sdram_input_efifo_module the_sdram_input_efifo_module
(
.almost_empty (almost_empty),
.almost_full (almost_full),
.clk (clk),
.empty (f_empty),
.full (za_waitrequest),
.rd (f_select),
.rd_data (fifo_read_data),
.reset_n (reset_n),
.wr ((~az_wr_n | ~az_rd_n) & !za_waitrequest),
.wr_data ({az_wr_n, az_addr, az_wr_n ? 2'b0 : az_be_n, az_data})
);
assign f_bank = {f_addr[21],f_addr[8]};
// Refresh/init counter.
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
refresh_counter <= 5000;
else if (refresh_counter == 0)
refresh_counter <= 781;
else
refresh_counter <= refresh_counter - 1'b1;
end
// Refresh request signal.
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
refresh_request <= 0;
else if (1)
refresh_request <= ((refresh_counter == 0) | refresh_request) & ~ack_refresh_request & init_done;
end
// Generate an Interrupt if two ref_reqs occur before one ack_refresh_request
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
za_cannotrefresh <= 0;
else if (1)
za_cannotrefresh <= (refresh_counter == 0) & refresh_request;
end
// Initialization-done flag.
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
init_done <= 0;
else if (1)
init_done <= init_done | (i_state == 3'b101);
end
// **** Init FSM ****
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
begin
i_state <= 3'b000;
i_next <= 3'b000;
i_cmd <= 4'b1111;
i_addr <= {12{1'b1}};
i_count <= {3{1'b0}};
end
else
begin
i_addr <= {12{1'b1}};
case (i_state) // synthesis parallel_case full_case
3'b000: begin
i_cmd <= 4'b1111;
i_refs <= 3'b0;
//Wait for refresh count-down after reset
if (refresh_counter == 0)
i_state <= 3'b001;
end // 3'b000
3'b001: begin
i_state <= 3'b011;
i_cmd <= {{1{1'b0}},3'h2};
i_count <= 0;
i_next <= 3'b010;
end // 3'b001
3'b010: begin
i_cmd <= {{1{1'b0}},3'h1};
i_refs <= i_refs + 1'b1;
i_state <= 3'b011;
i_count <= 3;
// Count up init_refresh_commands
if (i_refs == 3'h1)
i_next <= 3'b111;
else
i_next <= 3'b010;
end // 3'b010
3'b011: begin
i_cmd <= {{1{1'b0}},3'h7};
//WAIT til safe to Proceed...
if (i_count > 1)
i_count <= i_count - 1'b1;
else
i_state <= i_next;
end // 3'b011
3'b101: begin
i_state <= 3'b101;
end // 3'b101
3'b111: begin
i_state <= 3'b011;
i_cmd <= {{1{1'b0}},3'h0};
i_addr <= {{2{1'b0}},1'b0,2'b00,3'h3,4'h0};
i_count <= 4;
i_next <= 3'b101;
end // 3'b111
default: begin
i_state <= 3'b000;
end // default
endcase // i_state
end
end
assign active_bank = {active_addr[21],active_addr[8]};
assign csn_match = active_cs_n == f_cs_n;
assign rnw_match = active_rnw == f_rnw;
assign bank_match = active_bank == f_bank;
assign row_match = {active_addr[20 : 9]} == {f_addr[20 : 9]};
assign pending = csn_match && rnw_match && bank_match && row_match && !f_empty;
assign cas_addr = f_select ? { {4{1'b0}},f_addr[7 : 0] } : { {4{1'b0}},active_addr[7 : 0] };
// **** Main FSM ****
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
begin
m_state <= 9'b000000001;
m_next <= 9'b000000001;
m_cmd <= 4'b1111;
m_bank <= 2'b00;
m_addr <= 12'b000000000000;
m_data <= 16'b0000000000000000;
m_dqm <= 2'b00;
m_count <= 3'b000;
ack_refresh_request <= 1'b0;
f_pop <= 1'b0;
oe <= 1'b0;
end
else
begin
f_pop <= 1'b0;
oe <= 1'b0;
case (m_state) // synthesis parallel_case full_case
9'b000000001: begin
//Wait for init-fsm to be done...
if (init_done)
begin
//Hold bus if another cycle ended to arf.
if (refresh_request)
m_cmd <= {{1{1'b0}},3'h7};
else
m_cmd <= 4'b1111;
ack_refresh_request <= 1'b0;
//Wait for a read/write request.
if (refresh_request)
begin
m_state <= 9'b001000000;
m_next <= 9'b010000000;
m_count <= 0;
active_cs_n <= 1'b1;
end
else if (!f_empty)
begin
f_pop <= 1'b1;
active_cs_n <= f_cs_n;
active_rnw <= f_rnw;
active_addr <= f_addr;
active_data <= f_data;
active_dqm <= f_dqm;
m_state <= 9'b000000010;
end
end
else
begin
m_addr <= i_addr;
m_state <= 9'b000000001;
m_next <= 9'b000000001;
m_cmd <= i_cmd;
end
end // 9'b000000001
9'b000000010: begin
m_state <= 9'b000000100;
m_cmd <= {csn_decode,3'h3};
m_bank <= active_bank;
m_addr <= active_addr[20 : 9];
m_data <= active_data;
m_dqm <= active_dqm;
m_count <= 1;
m_next <= active_rnw ? 9'b000001000 : 9'b000010000;
end // 9'b000000010
9'b000000100: begin
// precharge all if arf, else precharge csn_decode
if (m_next == 9'b010000000)
m_cmd <= {{1{1'b0}},3'h7};
else
m_cmd <= {csn_decode,3'h7};
//Count down til safe to Proceed...
if (m_count > 1)
m_count <= m_count - 1'b1;
else
m_state <= m_next;
end // 9'b000000100
9'b000001000: begin
m_cmd <= {csn_decode,3'h5};
m_bank <= f_select ? f_bank : active_bank;
m_dqm <= f_select ? f_dqm : active_dqm;
m_addr <= cas_addr;
//Do we have a transaction pending?
if (pending)
begin
//if we need to ARF, bail, else spin
if (refresh_request)
begin
m_state <= 9'b000000100;
m_next <= 9'b000000001;
m_count <= 2;
end
else
begin
f_pop <= 1'b1;
active_cs_n <= f_cs_n;
active_rnw <= f_rnw;
active_addr <= f_addr;
active_data <= f_data;
active_dqm <= f_dqm;
end
end
else
begin
//correctly end RD spin cycle if fifo mt
if (~pending & f_pop)
m_cmd <= {csn_decode,3'h7};
m_state <= 9'b100000000;
end
end // 9'b000001000
9'b000010000: begin
m_cmd <= {csn_decode,3'h4};
oe <= 1'b1;
m_data <= f_select ? f_data : active_data;
m_dqm <= f_select ? f_dqm : active_dqm;
m_bank <= f_select ? f_bank : active_bank;
m_addr <= cas_addr;
//Do we have a transaction pending?
if (pending)
begin
//if we need to ARF, bail, else spin
if (refresh_request)
begin
m_state <= 9'b000000100;
m_next <= 9'b000000001;
m_count <= 1;
end
else
begin
f_pop <= 1'b1;
active_cs_n <= f_cs_n;
active_rnw <= f_rnw;
active_addr <= f_addr;
active_data <= f_data;
active_dqm <= f_dqm;
end
end
else
begin
//correctly end WR spin cycle if fifo empty
if (~pending & f_pop)
begin
m_cmd <= {csn_decode,3'h7};
oe <= 1'b0;
end
m_state <= 9'b100000000;
end
end // 9'b000010000
9'b000100000: begin
m_cmd <= {csn_decode,3'h7};
//Count down til safe to Proceed...
if (m_count > 1)
m_count <= m_count - 1'b1;
else
begin
m_state <= 9'b001000000;
m_count <= 0;
end
end // 9'b000100000
9'b001000000: begin
m_state <= 9'b000000100;
m_addr <= {12{1'b1}};
// precharge all if arf, else precharge csn_decode
if (refresh_request)
m_cmd <= {{1{1'b0}},3'h2};
else
m_cmd <= {csn_decode,3'h2};
end // 9'b001000000
9'b010000000: begin
ack_refresh_request <= 1'b1;
m_state <= 9'b000000100;
m_cmd <= {{1{1'b0}},3'h1};
m_count <= 3;
m_next <= 9'b000000001;
end // 9'b010000000
9'b100000000: begin
m_cmd <= {csn_decode,3'h7};
//if we need to ARF, bail, else spin
if (refresh_request)
begin
m_state <= 9'b000000100;
m_next <= 9'b000000001;
m_count <= 1;
end
else //wait for fifo to have contents
if (!f_empty)
//Are we 'pending' yet?
if (csn_match && rnw_match && bank_match && row_match)
begin
m_state <= f_rnw ? 9'b000001000 : 9'b000010000;
f_pop <= 1'b1;
active_cs_n <= f_cs_n;
active_rnw <= f_rnw;
active_addr <= f_addr;
active_data <= f_data;
active_dqm <= f_dqm;
end
else
begin
m_state <= 9'b000100000;
m_next <= 9'b000000001;
m_count <= 1;
end
end // 9'b100000000
// synthesis translate_off
default: begin
m_state <= m_state;
m_cmd <= 4'b1111;
f_pop <= 1'b0;
oe <= 1'b0;
end // default
// synthesis translate_on
endcase // m_state
end
end
assign rd_strobe = m_cmd[2 : 0] == 3'h5;
//Track RD Req's based on cas_latency w/shift reg
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
rd_valid <= {3{1'b0}};
else
rd_valid <= (rd_valid << 1) | { {2{1'b0}}, rd_strobe };
end
// Register dq data.
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
za_data <= 0;
else if (1)
za_data <= zs_dq;
end
// Delay za_valid to match registered data.
always @(posedge clk or negedge reset_n)
begin
if (reset_n == 0)
za_valid <= 0;
else if (1)
za_valid <= rd_valid[2];
end
assign cmd_code = m_cmd[2 : 0];
assign cmd_all = m_cmd;
//synthesis translate_off
//////////////// SIMULATION-ONLY CONTENTS
assign txt_code = (cmd_code == 3'h0)? 24'h4c4d52 :
(cmd_code == 3'h1)? 24'h415246 :
(cmd_code == 3'h2)? 24'h505245 :
(cmd_code == 3'h3)? 24'h414354 :
(cmd_code == 3'h4)? 24'h205752 :
(cmd_code == 3'h5)? 24'h205244 :
(cmd_code == 3'h6)? 24'h425354 :
(cmd_code == 3'h7)? 24'h4e4f50 :
24'h424144;
assign CODE = &(cmd_all|4'h7) ? 24'h494e48 : txt_code;
//////////////// END SIMULATION-ONLY CONTENTS
//synthesis translate_on
endmodule