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super6502/hw/efinix_fpga/simulation/generic_sdr.v
2023-09-21 19:23:31 -07:00

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/**************************************************************************
*
* File Name: sdr.v
* Version: 2.2
* Date: October 12th, 2010
* Model: BUS Functional
* Simulator: Model Technology
*
* Dependencies: None
*
* Email: modelsupport@micron.com
* Company: Micron Technology, Inc.
*
* Description: Micron SDRAM Verilog model
*
* Limitation: - Doesn't check for refresh timing
*
* Note: - Set simulator resolution to "ps" accuracy
* - Set Debug = 0 to disable $display messages
*
* Disclaimer: THESE DESIGNS ARE PROVIDED "AS IS" WITH NO WARRANTY
* WHATSOEVER AND MICRON SPECIFICALLY DISCLAIMS ANY
* IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR
* A PARTICULAR PURPOSE, OR AGAINST INFRINGEMENT.
*
* Copyright <20> 2001 Micron Semiconductor Products, Inc.
* All rights researved
*
* Rev Author Date Changes
* --- -------------------------- ---------------------------------------
* 2.3 SH 05/12/2016 - Update tAC, tHZ timing
* Micron Technology Inc.
*
* 2.2 SH 10/12/2010 - Combine all parts into sdr_parameters.vh
* Micron Technology Inc.
*
* 2.1 SH 06/06/2002 - Typo in bank multiplex
* Micron Technology Inc.
*
* 2.0 SH 04/30/2002 - Second release
* Micron Technology Inc.
*
**************************************************************************/
`timescale 1ns / 1ps
`define x8
`define CLK_200
`define SYS_CLK_100
module generic_sdr (Dq, Addr, Ba, Clk, Cke, Cs_n, Ras_n, Cas_n, We_n, Dqm);
`include "super6502_sdram_controller_define.vh"
parameter tCK = 1000/fCK_MHz; // tCK ns Nominal Clock Cycle Time
`ifdef CLK_200
parameter real tAC3 = 4.5; // tAC3 ns Access time from CLK (pos edge) CL = 3
parameter real tAC2 = 4.5; // tAC2 ns Access time from CLK (pos edge) CL = 2
parameter real tAC1 = 4.5; // tAC1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`elsif CLK_166
parameter real tAC3 = 5.4; // tAC3 ns Access time from CLK (pos edge) CL = 3
parameter real tAC2 = 5.4; // tAC2 ns Access time from CLK (pos edge) CL = 2
parameter real tAC1 = 5.4; // tAC1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`elsif CLK_133
parameter real tAC3 = 6.0; // tAC3 ns Access time from CLK (pos edge) CL = 3
parameter real tAC2 = 6.0; // tAC2 ns Access time from CLK (pos edge) CL = 2
parameter real tAC1 = 6.0; // tAC1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`endif
`ifdef CLK_200
parameter real tHZ3 = 4.5; // tHZ3 ns Data Out High Z time - CL = 3
parameter real tHZ2 = 4.5; // tHZ2 ns Data Out High Z time - CL = 2
parameter real tHZ1 = 4.5; // tHZ1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`elsif CLK_166
parameter real tHZ3 = 5.4; // tHZ3 ns Data Out High Z time - CL = 3
parameter real tHZ2 = 5.4; // tHZ2 ns Data Out High Z time - CL = 2
parameter real tHZ1 = 5.4; // tHZ1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`elsif CLK_133
parameter real tHZ3 = 6.0; // tHZ3 ns Data Out High Z time - CL = 3
parameter real tHZ2 = 6.0; // tHZ2 ns Data Out High Z time - CL = 2
parameter real tHZ1 = 6.0; // tHZ1 ns Parameter definition for compilation - CL = 1 illegal for sg75
`endif
parameter tOH = 2.7; // tOH ns Data Out Hold time
parameter tRRD = 2.0; // tRRD tCK Active bank a to Active bank b command time (2 * tCK)
parameter tWRa = tCK; // tWR ns Write recovery time (auto-precharge mode - must add 1 CLK)
parameter tWRm = 2*tCK; // tWR ns Write recovery time
parameter ADDR_BITS = ROW_WIDTH; // Set this parameter to control how many Address bits are used
parameter ROW_BITS = ROW_WIDTH; // Set this parameter to control how many Row bits are used
parameter COL_BITS = COL_WIDTH; // Set this parameter to control how many Column bits are used
parameter DQ_BITS = DQ_WIDTH; // Set this parameter to control how many Data bits are used
parameter DM_BITS = 1; // Set this parameter to control how many DM bits are used
parameter BA_BITS = BA_WIDTH; // Bank bits
parameter mem_sizes = 2**(ROW_BITS+COL_BITS) - 1;
input Clk;
input Cke;
input Cs_n;
input Ras_n;
input Cas_n;
input We_n;
input [ADDR_BITS - 1 : 0] Addr;
input [BA_BITS - 1 : 0] Ba;
inout [DQ_BITS - 1 : 0] Dq;
input [DM_BITS - 1 : 0] Dqm;
reg [DQ_BITS - 1 : 0] Bank0 [0 : mem_sizes];
reg [DQ_BITS - 1 : 0] Bank1 [0 : mem_sizes];
reg [DQ_BITS - 1 : 0] Bank2 [0 : mem_sizes];
reg [DQ_BITS - 1 : 0] Bank3 [0 : mem_sizes];
reg [1 : 0] Bank_addr [0 : 3]; // Bank Address Pipeline
reg [COL_BITS - 1 : 0] Col_addr [0 : 3]; // Column Address Pipeline
reg [3 : 0] Command [0 : 3]; // Command Operation Pipeline
reg [1 : 0] Dqm_reg0, Dqm_reg1; // DQM Operation Pipeline
reg [ADDR_BITS - 1 : 0] B0_row_addr, B1_row_addr, B2_row_addr, B3_row_addr;
reg [ADDR_BITS - 1 : 0] Mode_reg;
reg [DQ_BITS - 1 : 0] Dq_reg, Dq_dqm;
reg [COL_BITS - 1 : 0] Col_temp, Burst_counter;
reg Act_b0, Act_b1, Act_b2, Act_b3; // Bank Activate
reg Pc_b0, Pc_b1, Pc_b2, Pc_b3; // Bank Precharge
reg [1 : 0] Bank_precharge [0 : 3]; // Precharge Command
reg A10_precharge [0 : 3]; // Addr[10] = 1 (All banks)
reg Auto_precharge [0 : 3]; // RW Auto Precharge (Bank)
reg Read_precharge [0 : 3]; // R Auto Precharge
reg Write_precharge [0 : 3]; // W Auto Precharge
reg RW_interrupt_read [0 : 3]; // RW Interrupt Read with Auto Precharge
reg RW_interrupt_write [0 : 3]; // RW Interrupt Write with Auto Precharge
reg [1 : 0] RW_interrupt_bank; // RW Interrupt Bank
integer RW_interrupt_counter [0 : 3]; // RW Interrupt Counter
integer Count_precharge [0 : 3]; // RW Auto Precharge Counter
reg Data_in_enable;
reg Data_out_enable;
reg [1 : 0] Bank, Prev_bank;
reg [ADDR_BITS - 1 : 0] Row;
reg [COL_BITS - 1 : 0] Col, Col_brst;
// Internal system clock
reg CkeZ, Sys_clk;
// Commands Decode
wire Active_enable = ~Cs_n & ~Ras_n & Cas_n & We_n;
wire Aref_enable = ~Cs_n & ~Ras_n & ~Cas_n & We_n;
wire Burst_term = ~Cs_n & Ras_n & Cas_n & ~We_n;
wire Mode_reg_enable = ~Cs_n & ~Ras_n & ~Cas_n & ~We_n;
wire Prech_enable = ~Cs_n & ~Ras_n & Cas_n & ~We_n;
wire Read_enable = ~Cs_n & Ras_n & ~Cas_n & We_n;
wire Write_enable = ~Cs_n & Ras_n & ~Cas_n & ~We_n;
// Burst Length Decode
wire Burst_length_1 = ~Mode_reg[2] & ~Mode_reg[1] & ~Mode_reg[0];
wire Burst_length_2 = ~Mode_reg[2] & ~Mode_reg[1] & Mode_reg[0];
wire Burst_length_4 = ~Mode_reg[2] & Mode_reg[1] & ~Mode_reg[0];
wire Burst_length_8 = ~Mode_reg[2] & Mode_reg[1] & Mode_reg[0];
wire Burst_length_f = Mode_reg[2] & Mode_reg[1] & Mode_reg[0];
// CAS Latency Decode
wire [2 : 0] Cas_latency = {Mode_reg[6], Mode_reg[5], Mode_reg[4]};
// Write Burst Mode
wire Write_burst_mode = Mode_reg[9];
wire Debug = 1'b1; // Debug messages : 1 = On
wire Dq_chk = Sys_clk & Data_in_enable; // Check setup/hold time for DQ
assign Dq = Dq_reg; // DQ buffer
// Commands Operation
`define ACT 0
`define NOP 1
`define READ 2
`define WRITE 3
`define PRECH 4
`define A_REF 5
`define BST 6
`define LMR 7
// These timing dynamically adjust based on CAS Latency
time tAC, tHZ;
// Timing Check variable
time MRD_chk;
time WR_chkm [0 : 3];
time RFC_chk, RRD_chk;
time RC_chk0, RC_chk1, RC_chk2, RC_chk3;
time RAS_chk0, RAS_chk1, RAS_chk2, RAS_chk3;
time RCD_chk0, RCD_chk1, RCD_chk2, RCD_chk3;
time RP_chk0, RP_chk1, RP_chk2, RP_chk3;
initial begin
Dq_reg = {DQ_BITS{1'bz}};
Data_in_enable = 0; Data_out_enable = 0;
Act_b0 = 1; Act_b1 = 1; Act_b2 = 1; Act_b3 = 1;
Pc_b0 = 0; Pc_b1 = 0; Pc_b2 = 0; Pc_b3 = 0;
WR_chkm[0] = 0; WR_chkm[1] = 0; WR_chkm[2] = 0; WR_chkm[3] = 0;
RW_interrupt_read[0] = 0; RW_interrupt_read[1] = 0; RW_interrupt_read[2] = 0; RW_interrupt_read[3] = 0;
RW_interrupt_write[0] = 0; RW_interrupt_write[1] = 0; RW_interrupt_write[2] = 0; RW_interrupt_write[3] = 0;
MRD_chk = 0; RFC_chk = 0; RRD_chk = 0;
RAS_chk0 = 0; RAS_chk1 = 0; RAS_chk2 = 0; RAS_chk3 = 0;
RCD_chk0 = 0; RCD_chk1 = 0; RCD_chk2 = 0; RCD_chk3 = 0;
RC_chk0 = 0; RC_chk1 = 0; RC_chk2 = 0; RC_chk3 = 0;
RP_chk0 = 0; RP_chk1 = 0; RP_chk2 = 0; RP_chk3 = 0;
$timeformat (-9, 1, " ns", 12);
end
// System clock generator
always begin
@ (posedge Clk) begin
Sys_clk = CkeZ;
CkeZ = Cke;
end
@ (negedge Clk) begin
Sys_clk = 1'b0;
end
end
// Adjust tAC, tHZ based on CAS Latency
always @ (Cas_latency) begin
case (Cas_latency)
1 : begin tAC = tAC1; tHZ = tHZ1; end
2 : begin tAC = tAC2; tHZ = tHZ2; end
3 : begin tAC = tAC3; tHZ = tHZ3; end
endcase
end
always @ (posedge Sys_clk) begin
// Internal Commamd Pipelined
Command[0] = Command[1];
Command[1] = Command[2];
Command[2] = Command[3];
Command[3] = `NOP;
Col_addr[0] = Col_addr[1];
Col_addr[1] = Col_addr[2];
Col_addr[2] = Col_addr[3];
Col_addr[3] = {COL_BITS{1'b0}};
Bank_addr[0] = Bank_addr[1];
Bank_addr[1] = Bank_addr[2];
Bank_addr[2] = Bank_addr[3];
Bank_addr[3] = 2'b0;
Bank_precharge[0] = Bank_precharge[1];
Bank_precharge[1] = Bank_precharge[2];
Bank_precharge[2] = Bank_precharge[3];
Bank_precharge[3] = 2'b0;
A10_precharge[0] = A10_precharge[1];
A10_precharge[1] = A10_precharge[2];
A10_precharge[2] = A10_precharge[3];
A10_precharge[3] = 1'b0;
// Dqm pipeline for Read
Dqm_reg0 = Dqm_reg1;
Dqm_reg1 = Dqm;
// Read or Write with Auto Precharge Counter
if (Auto_precharge[0] === 1'b1) begin
Count_precharge[0] = Count_precharge[0] + 1;
end
if (Auto_precharge[1] === 1'b1) begin
Count_precharge[1] = Count_precharge[1] + 1;
end
if (Auto_precharge[2] === 1'b1) begin
Count_precharge[2] = Count_precharge[2] + 1;
end
if (Auto_precharge[3] === 1'b1) begin
Count_precharge[3] = Count_precharge[3] + 1;
end
// Read or Write Interrupt Counter
if (RW_interrupt_write[0] === 1'b1) begin
RW_interrupt_counter[0] = RW_interrupt_counter[0] + 1;
end
if (RW_interrupt_write[1] === 1'b1) begin
RW_interrupt_counter[1] = RW_interrupt_counter[1] + 1;
end
if (RW_interrupt_write[2] === 1'b1) begin
RW_interrupt_counter[2] = RW_interrupt_counter[2] + 1;
end
if (RW_interrupt_write[3] === 1'b1) begin
RW_interrupt_counter[3] = RW_interrupt_counter[3] + 1;
end
// tMRD Counter
MRD_chk = MRD_chk + 1;
// Auto Refresh
if (Aref_enable === 1'b1) begin
if (Debug) begin
$display ("%m : at time %t AREF : Auto Refresh", $time);
end
// Auto Refresh to Auto Refresh
if ($time - RFC_chk < tRFC) begin
$display ("%m : at time %t ERROR: tRFC violation during Auto Refresh", $time);
end
// Precharge to Auto Refresh
if (($time - RP_chk0 < tRP) || ($time - RP_chk1 < tRP) ||
($time - RP_chk2 < tRP) || ($time - RP_chk3 < tRP)) begin
$display ("%m : at time %t ERROR: tRP violation during Auto Refresh", $time);
end
// Precharge to Refresh
if (Pc_b0 === 1'b0 || Pc_b1 === 1'b0 || Pc_b2 === 1'b0 || Pc_b3 === 1'b0) begin
$display ("%m : at time %t ERROR: All banks must be Precharge before Auto Refresh", $time);
end
// Load Mode Register to Auto Refresh
if (MRD_chk < tMRD) begin
$display ("%m : at time %t ERROR: tMRD violation during Auto Refresh", $time);
end
// Record Current tRFC time
RFC_chk = $time;
end
// Load Mode Register
if (Mode_reg_enable === 1'b1) begin
// Register Mode
Mode_reg = Addr;
// Decode CAS Latency, Burst Length, Burst Type, and Write Burst Mode
if (Debug) begin
$display ("%m : at time %t LMR : Load Mode Register", $time);
// CAS Latency
case (Addr[6 : 4])
3'b010 : $display ("%m : CAS Latency = 2");
3'b011 : $display ("%m : CAS Latency = 3");
default : $display ("%m : CAS Latency = Reserved");
endcase
// Burst Length
case (Addr[2 : 0])
3'b000 : $display ("%m : Burst Length = 1");
3'b001 : $display ("%m : Burst Length = 2");
3'b010 : $display ("%m : Burst Length = 4");
3'b011 : $display ("%m : Burst Length = 8");
3'b111 : $display ("%m : Burst Length = Full");
default : $display ("%m : Burst Length = Reserved");
endcase
// Burst Type
if (Addr[3] === 1'b0) begin
$display ("%m : Burst Type = Sequential");
end else if (Addr[3] === 1'b1) begin
$display ("%m : Burst Type = Interleaved");
end else begin
$display ("%m : Burst Type = Reserved");
end
// Write Burst Mode
if (Addr[9] === 1'b0) begin
$display ("%m : Write Burst Mode = Programmed Burst Length");
end else if (Addr[9] === 1'b1) begin
$display ("%m : Write Burst Mode = Single Location Access");
end else begin
$display ("%m : Write Burst Mode = Reserved");
end
end
// Precharge to Load Mode Register
if (Pc_b0 === 1'b0 && Pc_b1 === 1'b0 && Pc_b2 === 1'b0 && Pc_b3 === 1'b0) begin
$display ("%m : at time %t ERROR: all banks must be Precharge before Load Mode Register", $time);
end
// Precharge to Load Mode Register
if (($time - RP_chk0 < tRP) || ($time - RP_chk1 < tRP) ||
($time - RP_chk2 < tRP) || ($time - RP_chk3 < tRP)) begin
$display ("%m : at time %t ERROR: tRP violation during Load Mode Register", $time);
end
// Auto Refresh to Load Mode Register
if ($time - RFC_chk < tRFC) begin
$display ("%m : at time %t ERROR: tRFC violation during Load Mode Register", $time);
end
// Load Mode Register to Load Mode Register
if (MRD_chk < tMRD) begin
$display ("%m : at time %t ERROR: tMRD violation during Load Mode Register", $time);
end
// Reset MRD Counter
MRD_chk = 0;
end
// Active Block (Latch Bank Address and Row Address)
if (Active_enable === 1'b1) begin
// Activate an open bank can corrupt data
if ((Ba === 2'b00 && Act_b0 === 1'b1) || (Ba === 2'b01 && Act_b1 === 1'b1) ||
(Ba === 2'b10 && Act_b2 === 1'b1) || (Ba === 2'b11 && Act_b3 === 1'b1)) begin
$display ("%m : at time %t ERROR: Bank already activated -- data can be corrupted", $time);
end
// Activate Bank 0
if (Ba === 2'b00 && Pc_b0 === 1'b1) begin
// Debug Message
if (Debug) begin
$display ("%m : at time %t ACT : Bank = 0 Row = %d", $time, Addr);
end
// ACTIVE to ACTIVE command period
if ($time - RC_chk0 < tRC) begin
$display ("%m : at time %t ERROR: tRC violation during Activate bank 0", $time);
end
// Precharge to Activate Bank 0
if ($time - RP_chk0 < tRP) begin
$display ("%m : at time %t ERROR: tRP violation during Activate bank 0", $time);
end
// Record variables
Act_b0 = 1'b1;
Pc_b0 = 1'b0;
B0_row_addr = Addr [ADDR_BITS - 1 : 0];
RAS_chk0 = $time;
RC_chk0 = $time;
RCD_chk0 = $time;
end
if (Ba == 2'b01 && Pc_b1 == 1'b1) begin
// Debug Message
if (Debug) begin
$display ("%m : at time %t ACT : Bank = 1 Row = %d", $time, Addr);
end
// ACTIVE to ACTIVE command period
if ($time - RC_chk1 < tRC) begin
$display ("%m : at time %t ERROR: tRC violation during Activate bank 1", $time);
end
// Precharge to Activate Bank 1
if ($time - RP_chk1 < tRP) begin
$display ("%m : at time %t ERROR: tRP violation during Activate bank 1", $time);
end
// Record variables
Act_b1 = 1'b1;
Pc_b1 = 1'b0;
B1_row_addr = Addr [ADDR_BITS - 1 : 0];
RAS_chk1 = $time;
RC_chk1 = $time;
RCD_chk1 = $time;
end
if (Ba == 2'b10 && Pc_b2 == 1'b1) begin
// Debug Message
if (Debug) begin
$display ("%m : at time %t ACT : Bank = 2 Row = %d", $time, Addr);
end
// ACTIVE to ACTIVE command period
if ($time - RC_chk2 < tRC) begin
$display ("%m : at time %t ERROR: tRC violation during Activate bank 2", $time);
end
// Precharge to Activate Bank 2
if ($time - RP_chk2 < tRP) begin
$display ("%m : at time %t ERROR: tRP violation during Activate bank 2", $time);
end
// Record variables
Act_b2 = 1'b1;
Pc_b2 = 1'b0;
B2_row_addr = Addr [ADDR_BITS - 1 : 0];
RAS_chk2 = $time;
RC_chk2 = $time;
RCD_chk2 = $time;
end
if (Ba == 2'b11 && Pc_b3 == 1'b1) begin
// Debug Message
if (Debug) begin
$display ("%m : at time %t ACT : Bank = 3 Row = %d", $time, Addr);
end
// ACTIVE to ACTIVE command period
if ($time - RC_chk3 < tRC) begin
$display ("%m : at time %t ERROR: tRC violation during Activate bank 3", $time);
end
// Precharge to Activate Bank 3
if ($time - RP_chk3 < tRP) begin
$display ("%m : at time %t ERROR: tRP violation during Activate bank 3", $time);
end
// Record variables
Act_b3 = 1'b1;
Pc_b3 = 1'b0;
B3_row_addr = Addr [ADDR_BITS - 1 : 0];
RAS_chk3 = $time;
RC_chk3 = $time;
RCD_chk3 = $time;
end
// Active Bank A to Active Bank B
if ((Prev_bank != Ba) && ($time - RRD_chk < tRRD)) begin
$display ("%m : at time %t ERROR: tRRD violation during Activate bank = %d", $time, Ba);
end
// Auto Refresh to Activate
if ($time - RFC_chk < tRFC) begin
$display ("%m : at time %t ERROR: tRFC violation during Activate bank = %d", $time, Ba);
end
// Load Mode Register to Active
if (MRD_chk < tMRD ) begin
$display ("%m : at time %t ERROR: tMRD violation during Activate bank = %d", $time, Ba);
end
// Record variables for checking violation
RRD_chk = $time;
Prev_bank = Ba;
end
// Precharge Block
if (Prech_enable == 1'b1) begin
// Load Mode Register to Precharge
if ($time - MRD_chk < tMRD) begin
$display ("%m : at time %t ERROR: tMRD violaiton during Precharge", $time);
end
// Precharge Bank 0
if ((Addr[10] === 1'b1 || (Addr[10] === 1'b0 && Ba === 2'b00)) && Act_b0 === 1'b1) begin
Act_b0 = 1'b0;
Pc_b0 = 1'b1;
RP_chk0 = $time;
// Debug Message
if (Debug) begin
$display ("%m : at time %t PRECHARGE : Bank = 0", $time);
end
// Activate to Precharge
if ($time - RAS_chk0 < tRAS) begin
$display ("%m : at time %t ERROR: tRAS violation during Precharge", $time);
end
// tWR violation check for write
if ($time - WR_chkm[0] < tWRm) begin
$display ("%m : at time %t ERROR: tWR violation during Precharge", $time);
end
end
// Precharge Bank 1
if ((Addr[10] === 1'b1 || (Addr[10] === 1'b0 && Ba === 2'b01)) && Act_b1 === 1'b1) begin
Act_b1 = 1'b0;
Pc_b1 = 1'b1;
RP_chk1 = $time;
// Debug Message
if (Debug) begin
$display ("%m : at time %t PRECHARGE : Bank = 1", $time);
end
// Activate to Precharge
if ($time - RAS_chk1 < tRAS) begin
$display ("%m : at time %t ERROR: tRAS violation during Precharge", $time);
end
// tWR violation check for write
if ($time - WR_chkm[1] < tWRm) begin
$display ("%m : at time %t ERROR: tWR violation during Precharge", $time);
end
end
// Precharge Bank 2
if ((Addr[10] === 1'b1 || (Addr[10] === 1'b0 && Ba === 2'b10)) && Act_b2 === 1'b1) begin
Act_b2 = 1'b0;
Pc_b2 = 1'b1;
RP_chk2 = $time;
// Debug Message
if (Debug) begin
$display ("%m : at time %t PRECHARGE : Bank = 2", $time);
end
// Activate to Precharge
if ($time - RAS_chk2 < tRAS) begin
$display ("%m : at time %t ERROR: tRAS violation during Precharge", $time);
end
// tWR violation check for write
if ($time - WR_chkm[2] < tWRm) begin
$display ("%m : at time %t ERROR: tWR violation during Precharge", $time);
end
end
// Precharge Bank 3
if ((Addr[10] === 1'b1 || (Addr[10] === 1'b0 && Ba === 2'b11)) && Act_b3 === 1'b1) begin
Act_b3 = 1'b0;
Pc_b3 = 1'b1;
RP_chk3 = $time;
// Debug Message
if (Debug) begin
$display ("%m : at time %t PRECHARGE : Bank = 3", $time);
end
// Activate to Precharge
if ($time - RAS_chk3 < tRAS) begin
$display ("%m : at time %t ERROR: tRAS violation during Precharge", $time);
end
// tWR violation check for write
if ($time - WR_chkm[3] < tWRm) begin
$display ("%m : at time %t ERROR: tWR violation during Precharge", $time);
end
end
// Precharge truncation with DQM set
if ((Data_in_enable == 1'b1) && ~(&Dqm)) begin
$display ("%m : at time %t ERROR: DQM not asserted during Precharge truncation", $time);
end
// Terminate a Write Immediately (if same bank or all banks)
if (Data_in_enable === 1'b1 && (Bank === Ba || Addr[10] === 1'b1)) begin
Data_in_enable = 1'b0;
end
// Precharge Command Pipeline for Read
Command[Cas_latency - 1] = `PRECH;
Bank_precharge[Cas_latency - 1] = Ba;
A10_precharge[Cas_latency - 1] = Addr[10];
end
// Burst terminate
if (Burst_term === 1'b1) begin
// Terminate a Write Immediately
if (Data_in_enable == 1'b1) begin
Data_in_enable = 1'b0;
end
// Terminate a Read Depend on CAS Latency
Command[Cas_latency - 1] = `BST;
// Display debug message
if (Debug) begin
$display ("%m : at time %t BST : Burst Terminate",$time);
end
end
// Read, Write, Column Latch
if (Read_enable === 1'b1) begin
// Check to see if bank is open (ACT)
if ((Ba == 2'b00 && Pc_b0 == 1'b1) || (Ba == 2'b01 && Pc_b1 == 1'b1) ||
(Ba == 2'b10 && Pc_b2 == 1'b1) || (Ba == 2'b11 && Pc_b3 == 1'b1)) begin
$display("%m : at time %t ERROR: Bank is not Activated for Read", $time);
end
// Activate to Read or Write
if ((Ba == 2'b00) && ($time - RCD_chk0 < tRCD) ||
(Ba == 2'b01) && ($time - RCD_chk1 < tRCD) ||
(Ba == 2'b10) && ($time - RCD_chk2 < tRCD) ||
(Ba == 2'b11) && ($time - RCD_chk3 < tRCD)) begin
$display("%m : at time %t ERROR: tRCD violation during Read", $time);
end
// CAS Latency pipeline
Command[Cas_latency - 1] = `READ;
Col_addr[Cas_latency - 1] = Addr;
Bank_addr[Cas_latency - 1] = Ba;
// Read interrupt Write (terminate Write immediately)
if (Data_in_enable == 1'b1) begin
Data_in_enable = 1'b0;
// Interrupting a Write with Autoprecharge
if (Auto_precharge[RW_interrupt_bank] == 1'b1 && Write_precharge[RW_interrupt_bank] == 1'b1) begin
RW_interrupt_write[RW_interrupt_bank] = 1'b1;
RW_interrupt_counter[RW_interrupt_bank] = 0;
// Display debug message
if (Debug) begin
$display ("%m : at time %t NOTE : Read interrupt Write with Autoprecharge", $time);
end
end
end
// Read with Auto Precharge
if (Addr[10] == 1'b1) begin
Auto_precharge[Ba] = 1'b1;
Count_precharge[Ba] = 0;
RW_interrupt_bank = Ba;
Read_precharge[Ba] = 1'b1;
end
end
// Write Command
if (Write_enable == 1'b1) begin
// Activate to Write
if ((Ba == 2'b00 && Pc_b0 == 1'b1) || (Ba == 2'b01 && Pc_b1 == 1'b1) ||
(Ba == 2'b10 && Pc_b2 == 1'b1) || (Ba == 2'b11 && Pc_b3 == 1'b1)) begin
$display("%m : at time %t ERROR: Bank is not Activated for Write", $time);
end
// Activate to Read or Write
if ((Ba == 2'b00) && ($time - RCD_chk0 < tRCD) ||
(Ba == 2'b01) && ($time - RCD_chk1 < tRCD) ||
(Ba == 2'b10) && ($time - RCD_chk2 < tRCD) ||
(Ba == 2'b11) && ($time - RCD_chk3 < tRCD)) begin
$display("%m : at time %t ERROR: tRCD violation during Read", $time);
end
// Latch Write command, Bank, and Column
Command[0] = `WRITE;
Col_addr[0] = Addr;
Bank_addr[0] = Ba;
// Write interrupt Write (terminate Write immediately)
if (Data_in_enable == 1'b1) begin
Data_in_enable = 1'b0;
// Interrupting a Write with Autoprecharge
if (Auto_precharge[RW_interrupt_bank] == 1'b1 && Write_precharge[RW_interrupt_bank] == 1'b1) begin
RW_interrupt_write[RW_interrupt_bank] = 1'b1;
// Display debug message
if (Debug) begin
$display ("%m : at time %t NOTE : Read Bank %d interrupt Write Bank %d with Autoprecharge", $time, Ba, RW_interrupt_bank);
end
end
end
// Write interrupt Read (terminate Read immediately)
if (Data_out_enable == 1'b1) begin
Data_out_enable = 1'b0;
// Interrupting a Read with Autoprecharge
if (Auto_precharge[RW_interrupt_bank] == 1'b1 && Read_precharge[RW_interrupt_bank] == 1'b1) begin
RW_interrupt_read[RW_interrupt_bank] = 1'b1;
// Display debug message
if (Debug) begin
$display ("%m : at time %t NOTE : Write Bank %d interrupt Read Bank %d with Autoprecharge", $time, Ba, RW_interrupt_bank);
end
end
end
// Write with Auto Precharge
if (Addr[10] == 1'b1) begin
Auto_precharge[Ba] = 1'b1;
Count_precharge[Ba] = 0;
RW_interrupt_bank = Ba;
Write_precharge[Ba] = 1'b1;
end
end
/*
Write with Auto Precharge Calculation
The device start internal precharge when:
1. Meet minimum tRAS requirement
and 2. tWR cycle(s) after last valid data
or 3. Interrupt by a Read or Write (with or without Auto Precharge)
Note: Model is starting the internal precharge 1 cycle after they meet all the
requirement but tRP will be compensate for the time after the 1 cycle.
*/
if ((Auto_precharge[0] == 1'b1) && (Write_precharge[0] == 1'b1)) begin
if ((($time - RAS_chk0 >= tRAS) && // Case 1
(((Burst_length_1 == 1'b1 || Write_burst_mode == 1'b1) && Count_precharge [0] >= 1) || // Case 2
(Burst_length_2 == 1'b1 && Count_precharge [0] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge [0] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge [0] >= 8))) ||
(RW_interrupt_write[0] == 1'b1 && RW_interrupt_counter[0] >= 1)) begin // Case 3
Auto_precharge[0] = 1'b0;
Write_precharge[0] = 1'b0;
RW_interrupt_write[0] = 1'b0;
Pc_b0 = 1'b1;
Act_b0 = 1'b0;
RP_chk0 = $time + tWRa;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 0", $time);
end
end
end
if ((Auto_precharge[1] == 1'b1) && (Write_precharge[1] == 1'b1)) begin
if ((($time - RAS_chk1 >= tRAS) && // Case 1
(((Burst_length_1 == 1'b1 || Write_burst_mode == 1'b1) && Count_precharge [1] >= 1) || // Case 2
(Burst_length_2 == 1'b1 && Count_precharge [1] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge [1] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge [1] >= 8))) ||
(RW_interrupt_write[1] == 1'b1 && RW_interrupt_counter[1] >= 1)) begin // Case 3
Auto_precharge[1] = 1'b0;
Write_precharge[1] = 1'b0;
RW_interrupt_write[1] = 1'b0;
Pc_b1 = 1'b1;
Act_b1 = 1'b0;
RP_chk1 = $time + tWRa;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 1", $time);
end
end
end
if ((Auto_precharge[2] == 1'b1) && (Write_precharge[2] == 1'b1)) begin
if ((($time - RAS_chk2 >= tRAS) && // Case 1
(((Burst_length_1 == 1'b1 || Write_burst_mode == 1'b1) && Count_precharge [2] >= 1) || // Case 2
(Burst_length_2 == 1'b1 && Count_precharge [2] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge [2] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge [2] >= 8))) ||
(RW_interrupt_write[2] == 1'b1 && RW_interrupt_counter[2] >= 1)) begin // Case 3
Auto_precharge[2] = 1'b0;
Write_precharge[2] = 1'b0;
RW_interrupt_write[2] = 1'b0;
Pc_b2 = 1'b1;
Act_b2 = 1'b0;
RP_chk2 = $time + tWRa;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 2", $time);
end
end
end
if ((Auto_precharge[3] == 1'b1) && (Write_precharge[3] == 1'b1)) begin
if ((($time - RAS_chk3 >= tRAS) && // Case 1
(((Burst_length_1 == 1'b1 || Write_burst_mode == 1'b1) && Count_precharge [3] >= 1) || // Case 2
(Burst_length_2 == 1'b1 && Count_precharge [3] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge [3] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge [3] >= 8))) ||
(RW_interrupt_write[3] == 1'b1 && RW_interrupt_counter[3] >= 1)) begin // Case 3
Auto_precharge[3] = 1'b0;
Write_precharge[3] = 1'b0;
RW_interrupt_write[3] = 1'b0;
Pc_b3 = 1'b1;
Act_b3 = 1'b0;
RP_chk3 = $time + tWRa;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 3", $time);
end
end
end
// Read with Auto Precharge Calculation
// The device start internal precharge:
// 1. Meet minimum tRAS requirement
// and 2. CAS Latency - 1 cycles before last burst
// or 3. Interrupt by a Read or Write (with or without AutoPrecharge)
if ((Auto_precharge[0] == 1'b1) && (Read_precharge[0] == 1'b1)) begin
if ((($time - RAS_chk0 >= tRAS) && // Case 1
((Burst_length_1 == 1'b1 && Count_precharge[0] >= 1) || // Case 2
(Burst_length_2 == 1'b1 && Count_precharge[0] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge[0] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge[0] >= 8))) ||
(RW_interrupt_read[0] == 1'b1)) begin // Case 3
Pc_b0 = 1'b1;
Act_b0 = 1'b0;
RP_chk0 = $time;
Auto_precharge[0] = 1'b0;
Read_precharge[0] = 1'b0;
RW_interrupt_read[0] = 1'b0;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 0", $time);
end
end
end
if ((Auto_precharge[1] == 1'b1) && (Read_precharge[1] == 1'b1)) begin
if ((($time - RAS_chk1 >= tRAS) &&
((Burst_length_1 == 1'b1 && Count_precharge[1] >= 1) ||
(Burst_length_2 == 1'b1 && Count_precharge[1] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge[1] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge[1] >= 8))) ||
(RW_interrupt_read[1] == 1'b1)) begin
Pc_b1 = 1'b1;
Act_b1 = 1'b0;
RP_chk1 = $time;
Auto_precharge[1] = 1'b0;
Read_precharge[1] = 1'b0;
RW_interrupt_read[1] = 1'b0;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 1", $time);
end
end
end
if ((Auto_precharge[2] == 1'b1) && (Read_precharge[2] == 1'b1)) begin
if ((($time - RAS_chk2 >= tRAS) &&
((Burst_length_1 == 1'b1 && Count_precharge[2] >= 1) ||
(Burst_length_2 == 1'b1 && Count_precharge[2] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge[2] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge[2] >= 8))) ||
(RW_interrupt_read[2] == 1'b1)) begin
Pc_b2 = 1'b1;
Act_b2 = 1'b0;
RP_chk2 = $time;
Auto_precharge[2] = 1'b0;
Read_precharge[2] = 1'b0;
RW_interrupt_read[2] = 1'b0;
if (Debug) begin
$display ("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 2", $time);
end
end
end
if ((Auto_precharge[3] == 1'b1) && (Read_precharge[3] == 1'b1)) begin
if ((($time - RAS_chk3 >= tRAS) &&
((Burst_length_1 == 1'b1 && Count_precharge[3] >= 1) ||
(Burst_length_2 == 1'b1 && Count_precharge[3] >= 2) ||
(Burst_length_4 == 1'b1 && Count_precharge[3] >= 4) ||
(Burst_length_8 == 1'b1 && Count_precharge[3] >= 8))) ||
(RW_interrupt_read[3] == 1'b1)) begin
Pc_b3 = 1'b1;
Act_b3 = 1'b0;
RP_chk3 = $time;
Auto_precharge[3] = 1'b0;
Read_precharge[3] = 1'b0;
RW_interrupt_read[3] = 1'b0;
if (Debug) begin
$display("%m : at time %t NOTE : Start Internal Auto Precharge for Bank 3", $time);
end
end
end
// Internal Precharge or Bst
if (Command[0] == `PRECH) begin // Precharge terminate a read with same bank or all banks
if (Bank_precharge[0] == Bank || A10_precharge[0] == 1'b1) begin
if (Data_out_enable == 1'b1) begin
Data_out_enable = 1'b0;
end
end
end else if (Command[0] == `BST) begin // BST terminate a read to current bank
if (Data_out_enable == 1'b1) begin
Data_out_enable = 1'b0;
end
end
if (Data_out_enable == 1'b0) begin
Dq_reg <= #tOH {DQ_BITS{1'bz}};
end
// Detect Read or Write command
if (Command[0] == `READ) begin
Bank = Bank_addr[0];
Col = Col_addr[0];
Col_brst = Col_addr[0];
case (Bank_addr[0])
2'b00 : Row = B0_row_addr;
2'b01 : Row = B1_row_addr;
2'b10 : Row = B2_row_addr;
2'b11 : Row = B3_row_addr;
endcase
Burst_counter = 0;
Data_in_enable = 1'b0;
Data_out_enable = 1'b1;
end else if (Command[0] == `WRITE) begin
Bank = Bank_addr[0];
Col = Col_addr[0];
Col_brst = Col_addr[0];
case (Bank_addr[0])
2'b00 : Row = B0_row_addr;
2'b01 : Row = B1_row_addr;
2'b10 : Row = B2_row_addr;
2'b11 : Row = B3_row_addr;
endcase
Burst_counter = 0;
Data_in_enable = 1'b1;
Data_out_enable = 1'b0;
end
// DQ buffer (Driver/Receiver)
if (Data_in_enable == 1'b1) begin // Writing Data to Memory
// Array buffer
case (Bank)
2'b00 : Dq_dqm = Bank0 [{Row, Col}];
2'b01 : Dq_dqm = Bank1 [{Row, Col}];
2'b10 : Dq_dqm = Bank2 [{Row, Col}];
2'b11 : Dq_dqm = Bank3 [{Row, Col}];
endcase
// Dqm operation
`ifdef x4
if (Dqm[0] == 1'b0) begin
Dq_dqm [ 3 : 0] = Dq [ 3 : 0];
end
`elsif x8
if (Dqm[0] == 1'b0) begin
Dq_dqm [ 7 : 0] = Dq [ 7 : 0];
end
`elsif x16
if (Dqm[0] == 1'b0) begin
Dq_dqm [ 7 : 0] = Dq [ 7 : 0];
end
if (Dqm[1] == 1'b0) begin
Dq_dqm [15 : 8] = Dq [15 : 8];
end
`endif
// Write to memory
case (Bank)
2'b00 : Bank0 [{Row, Col}] = Dq_dqm;
2'b01 : Bank1 [{Row, Col}] = Dq_dqm;
2'b10 : Bank2 [{Row, Col}] = Dq_dqm;
2'b11 : Bank3 [{Row, Col}] = Dq_dqm;
endcase
// Display debug message
if (Dqm !== 2'b11) begin
// Record tWR for manual precharge
WR_chkm [Bank] = $time;
if (Debug) begin
$display("%m : at time %t WRITE: Bank = %d Row = %d, Col = %d, Data = %h", $time, Bank, Row, Col, Dq_dqm);
end
end else begin
if (Debug) begin
$display("%m : at time %t WRITE: Bank = %d Row = %d, Col = %d, Data = Hi-Z due to DQM", $time, Bank, Row, Col);
end
end
// Advance burst counter subroutine
#tHZ Burst_decode;
end else if (Data_out_enable == 1'b1) begin // Reading Data from Memory
// Array buffer
case (Bank)
2'b00 : Dq_dqm = Bank0[{Row, Col}];
2'b01 : Dq_dqm = Bank1[{Row, Col}];
2'b10 : Dq_dqm = Bank2[{Row, Col}];
2'b11 : Dq_dqm = Bank3[{Row, Col}];
endcase
// Dqm operation
`ifdef x4
if (Dqm_reg0 [0] == 1'b1) begin
Dq_dqm [ 3 : 0] = 4'bz;
end
`elsif x8
if (Dqm_reg0 [0] == 1'b1) begin
Dq_dqm [ 7 : 0] = 8'bz;
end
`elsif x16
if (Dqm_reg0 [0] == 1'b1) begin
Dq_dqm [ 7 : 0] = 8'bz;
end
if (Dqm_reg0 [1] == 1'b1) begin
Dq_dqm [15 : 8] = 8'bz;
end
`endif
// Display debug message
Dq_reg = #tAC Dq_dqm;
if (Debug) begin
$display("%m : at time %t READ : Bank = %d Row = %d, Col = %d, Dqm = %b, Data = %h", $time, Bank, Row, Col, Dqm_reg0, Dq_reg);
end
// Advance burst counter subroutine
Burst_decode;
end
end
// Burst counter decode
task Burst_decode;
begin
// Advance Burst Counter
Burst_counter = Burst_counter + 1;
// Burst Type
if (Mode_reg[3] == 1'b0) begin // Sequential Burst
Col_temp = Col + 1;
end else if (Mode_reg[3] == 1'b1) begin // Interleaved Burst
Col_temp[2] = Burst_counter[2] ^ Col_brst[2];
Col_temp[1] = Burst_counter[1] ^ Col_brst[1];
Col_temp[0] = Burst_counter[0] ^ Col_brst[0];
end
// Burst Length
if (Burst_length_2) begin // Burst Length = 2
Col [0] = Col_temp [0];
end else if (Burst_length_4) begin // Burst Length = 4
Col [1 : 0] = Col_temp [1 : 0];
end else if (Burst_length_8) begin // Burst Length = 8
Col [2 : 0] = Col_temp [2 : 0];
end else begin // Burst Length = FULL
Col = Col_temp;
end
// Burst Read Single Write
if (Write_burst_mode == 1'b1) begin
Data_in_enable = 1'b0;
end
// Data Counter
if (Burst_length_1 == 1'b1) begin
if (Burst_counter >= 1) begin
Data_in_enable = 1'b0;
Data_out_enable = 1'b0;
end
end else if (Burst_length_2 == 1'b1) begin
if (Burst_counter >= 2) begin
Data_in_enable = 1'b0;
Data_out_enable = 1'b0;
end
end else if (Burst_length_4 == 1'b1) begin
if (Burst_counter >= 4) begin
Data_in_enable = 1'b0;
Data_out_enable = 1'b0;
end
end else if (Burst_length_8 == 1'b1) begin
if (Burst_counter >= 8) begin
Data_in_enable = 1'b0;
Data_out_enable = 1'b0;
end
end
end
endtask
// Timing Parameters for -75 (133 MHz @ CL3)
specify
specparam
tAH = 0.8, // Addr, Ba Hold Time
tAS = 1.5, // Addr, Ba Setup Time
`ifdef CLK_166
tCK3 = 6,
`elsif CLK_133
tCK3 = 7.5,
`elsif CLK_100
tCK3 = 10,
`elsif CLK_200
tCK3 = 5,
`endif
tCH = 2.5, // Clock High-Level Width
tCL = 2.5, // Clock Low-Level Width
tCKH = 0.8, // CKE Hold Time
tCKS = 1.5, // CKE Setup Time
tCMH = 0.8, // CS#, RAS#, CAS#, WE#, DQM# Hold Time
tCMS = 1.5, // CS#, RAS#, CAS#, WE#, DQM# Setup Time
tDH = 0.8, // Data-in Hold Time
tDS = 1.5; // Data-in Setup Time
$width (posedge Clk, tCH);
$width (negedge Clk, tCL);
$period (negedge Clk, tCK3);
$period (posedge Clk, tCK3);
$setuphold(posedge Clk, Cke, tCKS, tCKH);
$setuphold(posedge Clk, Cs_n, tCMS, tCMH);
$setuphold(posedge Clk, Cas_n, tCMS, tCMH);
$setuphold(posedge Clk, Ras_n, tCMS, tCMH);
$setuphold(posedge Clk, We_n, tCMS, tCMH);
$setuphold(posedge Clk, Addr, tAS, tAH);
$setuphold(posedge Clk, Ba, tAS, tAH);
$setuphold(posedge Clk, Dqm, tCMS, tCMH);
$setuphold(posedge Dq_chk, Dq, tDS, tDH);
endspecify
endmodule