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vhdl/lib/SDRAM/ddr_sdr_v1_5/src/mt46v16m16.vhd
T
jens 6eb25882ba Intital revision 
git-svn-id: http://moon:8086/svn/vhdl/trunk@24 cc03376c-175c-47c8-b038-4cd826a8556b
2008-10-02 13:37:55 +00:00

1321 lines
53 KiB
VHDL
Raw Blame History

-----------------------------------------------------------------------------------------
--
-- File Name: MT46V16M16.VHD
-- Version: 2.1
-- Date: January 14th, 2002
-- Model: Behavioral
-- Simulator: NCDesktop - http://www.cadence.com
-- ModelSim PE - http://www.model.com
--
-- Dependencies: None
--
-- Author: Son P. Huynh
-- Email: sphuynh@micron.com
-- Phone: (208) 368-3825
-- Company: Micron Technology, Inc.
-- Part Number: MT46V16M16 (4 Mb x 16 x 4 Banks)
--
-- Description: Micron 256 Mb SDRAM DDR (Double Data Rate)
--
-- Limitation: Doesn't model internal refresh counter
--
-- Note:
--
-- 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 (c) 1998 Micron Semiconductor Products, Inc.
-- All rights researved
--
-- Rev Author Date Changes
-- --- ---------------------------- ---------- -------------------------------------
-- 2.1 Son P. Huynh 01/14/2002 - Fix Burst_counter
-- Micron Technology, Inc.
--
-- 2.0 Son P. Huynh 11/08/2001 - Second release
-- Micron Technology, Inc. - Rewrote and remove SHARED VARIABLE
--
-----------------------------------------------------------------------------------------
LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
USE IEEE.STD_LOGIC_ARITH.ALL;
ENTITY MT46V16M16 IS
GENERIC ( -- Timing for -75Z CL2
tCK : TIME := 7.500 ns;
tCH : TIME := 3.375 ns; -- 0.45*tCK
tCL : TIME := 3.375 ns; -- 0.45*tCK
tDH : TIME := 0.500 ns;
tDS : TIME := 0.500 ns;
tIH : TIME := 0.900 ns;
tIS : TIME := 0.900 ns;
tMRD : TIME := 15.000 ns;
tRAS : TIME := 40.000 ns;
tRAP : TIME := 20.000 ns;
tRC : TIME := 65.000 ns;
tRFC : TIME := 75.000 ns;
tRCD : TIME := 20.000 ns;
tRP : TIME := 20.000 ns;
tRRD : TIME := 15.000 ns;
tWR : TIME := 15.000 ns;
addr_bits : INTEGER := 13;
data_bits : INTEGER := 16;
cols_bits : INTEGER := 9
);
PORT (
Dq : INOUT STD_LOGIC_VECTOR (data_bits - 1 DOWNTO 0) := (OTHERS => 'Z');
Dqs : INOUT STD_LOGIC_VECTOR (1 DOWNTO 0) := "ZZ";
Addr : IN STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
Ba : IN STD_LOGIC_VECTOR (1 DOWNTO 0);
Clk : IN STD_LOGIC;
Clk_n : IN STD_LOGIC;
Cke : IN STD_LOGIC;
Cs_n : IN STD_LOGIC;
Ras_n : IN STD_LOGIC;
Cas_n : IN STD_LOGIC;
We_n : IN STD_LOGIC;
Dm : IN STD_LOGIC_VECTOR (1 DOWNTO 0)
);
END MT46V16M16;
ARCHITECTURE behave OF MT46V16M16 IS
-- Array for Read pipeline
TYPE Array_Read_cmnd IS ARRAY (8 DOWNTO 0) OF STD_LOGIC;
TYPE Array_Read_bank IS ARRAY (8 DOWNTO 0) OF STD_LOGIC_VECTOR (1 DOWNTO 0);
TYPE Array_Read_cols IS ARRAY (8 DOWNTO 0) OF STD_LOGIC_VECTOR (cols_bits - 1 DOWNTO 0);
-- Array for Write pipeline
TYPE Array_Write_cmnd IS ARRAY (2 DOWNTO 0) OF STD_LOGIC;
TYPE Array_Write_bank IS ARRAY (2 DOWNTO 0) OF STD_LOGIC_VECTOR (1 DOWNTO 0);
TYPE Array_Write_cols IS ARRAY (2 DOWNTO 0) OF STD_LOGIC_VECTOR (cols_bits - 1 DOWNTO 0);
-- Array for Auto Precharge
TYPE Array_Read_precharge IS ARRAY (3 DOWNTO 0) OF STD_LOGIC;
TYPE Array_Write_precharge IS ARRAY (3 DOWNTO 0) OF STD_LOGIC;
TYPE Array_Count_precharge IS ARRAY (3 DOWNTO 0) OF INTEGER;
-- Array for Manual Precharge
TYPE Array_A10_precharge IS ARRAY (8 DOWNTO 0) OF STD_LOGIC;
TYPE Array_Bank_precharge IS ARRAY (8 DOWNTO 0) OF STD_LOGIC_VECTOR (1 DOWNTO 0);
TYPE Array_Cmnd_precharge IS ARRAY (8 DOWNTO 0) OF STD_LOGIC;
-- Array for Burst Terminate
TYPE Array_Cmnd_bst IS ARRAY (8 DOWNTO 0) OF STD_LOGIC;
-- Array for Memory Access
TYPE Array_ram_type IS ARRAY (2**cols_bits - 1 DOWNTO 0) OF STD_LOGIC_VECTOR (data_bits - 1 DOWNTO 0);
TYPE Array_ram_pntr IS ACCESS Array_ram_type;
TYPE Array_ram_stor IS ARRAY (2**addr_bits - 1 DOWNTO 0) OF Array_ram_pntr;
-- Data pair
SIGNAL Dq_pair : STD_LOGIC_VECTOR (2 * data_bits - 1 DOWNTO 0);
SIGNAL Dm_pair : STD_LOGIC_VECTOR (3 DOWNTO 0);
-- Mode Register
SIGNAL Mode_reg : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0) := (OTHERS => '0');
-- Command Decode Variables
SIGNAL Active_enable, Aref_enable, Burst_term, Ext_mode_enable : STD_LOGIC := '0';
SIGNAL Mode_reg_enable, Prech_enable, Read_enable, Write_enable : STD_LOGIC := '0';
-- Burst Length Decode Variables
SIGNAL Burst_length_2, Burst_length_4, Burst_length_8, Burst_length_f : STD_LOGIC := '0';
-- Cas Latency Decode Variables
SIGNAL Cas_latency_15, Cas_latency_2, Cas_latency_25, Cas_latency_3, Cas_latency_4 : STD_LOGIC := '0';
-- Internal Control Signals
SIGNAL Cs_in, Ras_in, Cas_in, We_in : STD_LOGIC := '0';
-- System Clock
SIGNAL Sys_clk : STD_LOGIC := '0';
-- Dqs buffer
SIGNAL Dqs_out : STD_LOGIC_VECTOR (1 DOWNTO 0) := "ZZ";
BEGIN
-- Strip the strength
Cs_in <= To_X01 (Cs_n);
Ras_in <= To_X01 (Ras_n);
Cas_in <= To_X01 (Cas_n);
We_in <= To_X01 (We_n);
-- Commands Decode
Active_enable <= NOT(Cs_in) AND NOT(Ras_in) AND Cas_in AND We_in;
Aref_enable <= NOT(Cs_in) AND NOT(Ras_in) AND NOT(Cas_in) AND We_in;
Burst_term <= NOT(Cs_in) AND Ras_in AND Cas_in AND NOT(We_in);
Ext_mode_enable <= NOT(Cs_in) AND NOT(Ras_in) AND NOT(Cas_in) AND NOT(We_in) AND Ba(0) AND NOT(Ba(1));
Mode_reg_enable <= NOT(Cs_in) AND NOT(Ras_in) AND NOT(Cas_in) AND NOT(We_in) AND NOT(Ba(0)) AND NOT(Ba(1));
Prech_enable <= NOT(Cs_in) AND NOT(Ras_in) AND Cas_in AND NOT(We_in);
Read_enable <= NOT(Cs_in) AND Ras_in AND NOT(Cas_in) AND We_in;
Write_enable <= NOT(Cs_in) AND Ras_in AND NOT(Cas_in) AND NOT(We_in);
-- Burst Length Decode
Burst_length_2 <= NOT(Mode_reg(2)) AND NOT(Mode_reg(1)) AND Mode_reg(0);
Burst_length_4 <= NOT(Mode_reg(2)) AND Mode_reg(1) AND NOT(Mode_reg(0));
Burst_length_8 <= NOT(Mode_reg(2)) AND Mode_reg(1) AND Mode_reg(0);
Burst_length_f <= (Mode_reg(2)) AND Mode_reg(1) AND Mode_reg(0);
-- CAS Latency Decode
Cas_latency_15 <= Mode_reg(6) AND NOT(Mode_reg(5)) AND (Mode_reg(4));
Cas_latency_2 <= NOT(Mode_reg(6)) AND Mode_reg(5) AND NOT(Mode_reg(4));
Cas_latency_25 <= Mode_reg(6) AND Mode_reg(5) AND NOT(Mode_reg(4));
Cas_latency_3 <= NOT(Mode_reg(6)) AND Mode_reg(5) AND Mode_reg(4);
Cas_latency_4 <= (Mode_reg(6)) AND NOT(Mode_reg(5)) AND NOT(Mode_reg(4));
-- Dqs buffer
Dqs <= Dqs_out;
--
-- System Clock
--
int_clk : PROCESS (Clk, Clk_n)
VARIABLE ClkZ, CkeZ : STD_LOGIC := '0';
begin
IF Clk = '1' AND Clk_n = '0' THEN
ClkZ := '1';
CkeZ := Cke;
ELSIF Clk = '0' AND Clk_n = '1' THEN
ClkZ := '0';
END IF;
Sys_clk <= CkeZ AND ClkZ;
END PROCESS;
--
-- Main Process
--
state_register : PROCESS
-- Precharge Variables
VARIABLE Pc_b0, Pc_b1, Pc_b2, Pc_b3 : STD_LOGIC := '0';
-- Activate Variables
VARIABLE Act_b0, Act_b1, Act_b2, Act_b3 : STD_LOGIC := '1';
-- Data IO variables
VARIABLE Data_in_enable, Data_out_enable : STD_LOGIC := '0';
-- Internal address mux variables
VARIABLE Cols_brst : STD_LOGIC_VECTOR (2 DOWNTO 0);
VARIABLE Prev_bank : STD_LOGIC_VECTOR (1 DOWNTO 0) := "00";
VARIABLE Bank_addr : STD_LOGIC_VECTOR (1 DOWNTO 0) := "00";
VARIABLE Cols_addr : STD_LOGIC_VECTOR (cols_bits - 1 DOWNTO 0);
VARIABLE Rows_addr : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
VARIABLE B0_row_addr : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
VARIABLE B1_row_addr : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
VARIABLE B2_row_addr : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
VARIABLE B3_row_addr : STD_LOGIC_VECTOR (addr_bits - 1 DOWNTO 0);
-- DLL Reset variables
VARIABLE DLL_enable : STD_LOGIC := '0';
VARIABLE DLL_reset : STD_LOGIC := '0';
VARIABLE DLL_done : STD_LOGIC := '0';
VARIABLE DLL_count : INTEGER := 0;
-- Timing Check
VARIABLE MRD_chk : TIME := 0 ns;
VARIABLE RFC_chk : TIME := 0 ns;
VARIABLE RRD_chk : TIME := 0 ns;
VARIABLE RAS_chk0, RAS_chk1, RAS_chk2, RAS_chk3 : TIME := 0 ns;
VARIABLE RAP_chk0, RAP_chk1, RAP_chk2, RAP_chk3 : TIME := 0 ns;
VARIABLE RC_chk0, RC_chk1, RC_chk2, RC_chk3 : TIME := 0 ns;
VARIABLE RCD_chk0, RCD_chk1, RCD_chk2, RCD_chk3 : TIME := 0 ns;
VARIABLE RP_chk0, RP_chk1, RP_chk2, RP_chk3 : TIME := 0 ns;
VARIABLE WR_chk0, WR_chk1, WR_chk2, WR_chk3 : TIME := 0 ns;
-- Read pipeline variables
VARIABLE Read_cmnd : Array_Read_cmnd;
VARIABLE Read_bank : Array_Read_bank;
VARIABLE Read_cols : Array_Read_cols;
-- Write pipeline variables
VARIABLE Write_cmnd : Array_Write_cmnd;
VARIABLE Write_bank : Array_Write_bank;
VARIABLE Write_cols : Array_Write_cols;
-- Auto Precharge variables
VARIABLE Read_precharge : Array_Read_precharge := ('0' & '0' & '0' & '0');
VARIABLE Write_precharge : Array_Write_precharge := ('0' & '0' & '0' & '0');
VARIABLE Count_precharge : Array_Count_precharge := ( 0 & 0 & 0 & 0 );
-- Manual Precharge variables
VARIABLE A10_precharge : Array_A10_precharge;
VARIABLE Bank_precharge : Array_Bank_precharge;
VARIABLE Cmnd_precharge : Array_Cmnd_precharge;
-- Burst Terminate variable
VARIABLE Cmnd_bst : Array_Cmnd_bst;
-- Memory Banks
VARIABLE Bank0 : Array_ram_stor;
VARIABLE Bank1 : Array_ram_stor;
VARIABLE Bank2 : Array_ram_stor;
VARIABLE Bank3 : Array_ram_stor;
-- Burst Counter
VARIABLE Burst_counter : STD_LOGIC_VECTOR (cols_bits - 1 DOWNTO 0);
-- Internal Dqs initialize
VARIABLE Dqs_int : STD_LOGIC := '0';
-- Data buffer for DM Mask
VARIABLE Data_buf : STD_LOGIC_VECTOR (data_bits - 1 DOWNTO 0) := (OTHERS => 'Z');
--
-- Initialize empty rows
--
PROCEDURE Init_mem (Bank : STD_LOGIC_VECTOR; Row_index : INTEGER) IS
VARIABLE i, j : INTEGER := 0;
BEGIN
IF Bank = "00" THEN
IF Bank0 (Row_index) = NULL THEN -- Check to see if row empty
Bank0 (Row_index) := NEW Array_ram_type; -- Open new row for access
FOR i IN (2**cols_bits - 1) DOWNTO 0 LOOP -- Filled row with zeros
FOR j IN (data_bits - 1) DOWNTO 0 LOOP
Bank0 (Row_index) (i) (j) := '0';
END LOOP;
END LOOP;
END IF;
ELSIF Bank = "01" THEN
IF Bank1 (Row_index) = NULL THEN
Bank1 (Row_index) := NEW Array_ram_type;
FOR i IN (2**cols_bits - 1) DOWNTO 0 LOOP
FOR j IN (data_bits - 1) DOWNTO 0 LOOP
Bank1 (Row_index) (i) (j) := '0';
END LOOP;
END LOOP;
END IF;
ELSIF Bank = "10" THEN
IF Bank2 (Row_index) = NULL THEN
Bank2 (Row_index) := NEW Array_ram_type;
FOR i IN (2**cols_bits - 1) DOWNTO 0 LOOP
FOR j IN (data_bits - 1) DOWNTO 0 LOOP
Bank2 (Row_index) (i) (j) := '0';
END LOOP;
END LOOP;
END IF;
ELSIF Bank = "11" THEN
IF Bank3 (Row_index) = NULL THEN
Bank3 (Row_index) := NEW Array_ram_type;
FOR i IN (2**cols_bits - 1) DOWNTO 0 LOOP
FOR j IN (data_bits - 1) DOWNTO 0 LOOP
Bank3 (Row_index) (i) (j) := '0';
END LOOP;
END LOOP;
END IF;
END IF;
END;
--
-- Burst Counter
--
PROCEDURE Burst_decode IS
VARIABLE Cols_temp : STD_LOGIC_VECTOR (cols_bits - 1 DOWNTO 0) := (OTHERS => '0');
BEGIN
-- Advance burst counter
Burst_counter := Burst_counter + 1;
-- Burst Type
IF Mode_reg (3) = '0' THEN
Cols_temp := Cols_addr + 1;
ELSIF Mode_reg (3) = '1' THEN
Cols_temp (2) := Burst_counter (2) XOR Cols_brst (2);
Cols_temp (1) := Burst_counter (1) XOR Cols_brst (1);
Cols_temp (0) := Burst_counter (0) XOR Cols_brst (0);
END IF;
-- Burst Length
IF Burst_length_2 = '1' THEN
Cols_addr (0) := Cols_temp (0);
ELSIF Burst_length_4 = '1' THEN
Cols_addr (1 DOWNTO 0) := Cols_temp (1 DOWNTO 0);
ELSIF Burst_length_8 = '1' THEN
Cols_addr (2 DOWNTO 0) := Cols_temp (2 DOWNTO 0);
ELSE
Cols_addr := Cols_temp;
END IF;
-- Data counter
IF Burst_length_2 = '1' THEN
IF Burst_counter >= 2 THEN
IF Data_in_enable = '1' THEN
Data_in_enable := '0';
ELSIF Data_out_enable = '1' THEN
Data_out_enable := '0';
END IF;
END IF;
ELSIF Burst_length_4 = '1' THEN
IF Burst_counter >= 4 THEN
IF Data_in_enable = '1' THEN
Data_in_enable := '0';
ELSIF Data_out_enable = '1' THEN
Data_out_enable := '0';
END IF;
END IF;
ELSIF Burst_length_8 = '1' THEN
IF Burst_counter >= 8 THEN
IF Data_in_enable = '1' THEN
Data_in_enable := '0';
ELSIF Data_out_enable = '1' THEN
Data_out_enable := '0';
END IF;
END IF;
END IF;
END;
BEGIN
WAIT ON Sys_clk;
--
-- Manual Precharge Pipeline
--
IF ((Sys_clk'EVENT AND Sys_clk = '0') OR (Sys_clk'EVENT AND Sys_clk = '1')) THEN
-- A10 Precharge Pipeline
A10_precharge(0) := A10_precharge(1);
A10_precharge(1) := A10_precharge(2);
A10_precharge(2) := A10_precharge(3);
A10_precharge(3) := A10_precharge(4);
A10_precharge(4) := A10_precharge(5);
A10_precharge(5) := A10_precharge(6);
A10_precharge(6) := A10_precharge(7);
A10_precharge(7) := A10_precharge(8);
A10_precharge(8) := '0';
-- Bank Precharge Pipeline
Bank_precharge(0) := Bank_precharge(1);
Bank_precharge(1) := Bank_precharge(2);
Bank_precharge(2) := Bank_precharge(3);
Bank_precharge(3) := Bank_precharge(4);
Bank_precharge(4) := Bank_precharge(5);
Bank_precharge(5) := Bank_precharge(6);
Bank_precharge(6) := Bank_precharge(7);
Bank_precharge(7) := Bank_precharge(8);
Bank_precharge(8) := "00";
-- Command Precharge Pipeline
Cmnd_precharge(0) := Cmnd_precharge(1);
Cmnd_precharge(1) := Cmnd_precharge(2);
Cmnd_precharge(2) := Cmnd_precharge(3);
Cmnd_precharge(3) := Cmnd_precharge(4);
Cmnd_precharge(4) := Cmnd_precharge(5);
Cmnd_precharge(5) := Cmnd_precharge(6);
Cmnd_precharge(6) := Cmnd_precharge(7);
Cmnd_precharge(7) := Cmnd_precharge(8);
Cmnd_precharge(8) := '0';
-- Terminate Read if same bank or all banks
IF ((Cmnd_precharge (0) = '1') AND
(Bank_precharge (0) = Bank_addr OR A10_precharge (0) = '1') AND
(Data_out_enable = '1')) THEN
Data_out_enable := '0';
END IF;
END IF;
--
-- Burst Terminate Pipeline
--
IF ((Sys_clk'EVENT AND Sys_clk = '0') OR (Sys_clk'EVENT AND Sys_clk = '1')) THEN
-- Burst Terminate pipeline
Cmnd_bst (0) := Cmnd_bst (1);
Cmnd_bst (1) := Cmnd_bst (2);
Cmnd_bst (2) := Cmnd_bst (3);
Cmnd_bst (3) := Cmnd_bst (4);
Cmnd_bst (4) := Cmnd_bst (5);
Cmnd_bst (5) := Cmnd_bst (6);
Cmnd_bst (6) := Cmnd_bst (7);
Cmnd_bst (7) := Cmnd_bst (8);
Cmnd_bst (8) := '0';
-- Terminate current Read
IF ((Cmnd_bst (0) = '1') AND (Data_out_enable = '1')) THEN
Data_out_enable := '0';
END IF;
END IF;
--
-- Dq and Dqs Drivers
--
IF ((Sys_clk'EVENT AND Sys_clk = '0') OR (Sys_clk'EVENT AND Sys_clk = '1')) THEN
-- Read Command Pipeline
Read_cmnd (0) := Read_cmnd (1);
Read_cmnd (1) := Read_cmnd (2);
Read_cmnd (2) := Read_cmnd (3);
Read_cmnd (3) := Read_cmnd (4);
Read_cmnd (4) := Read_cmnd (5);
Read_cmnd (5) := Read_cmnd (6);
Read_cmnd (6) := Read_cmnd (7);
Read_cmnd (7) := Read_cmnd (8);
Read_cmnd (8) := '0';
-- Read Bank Pipeline
Read_bank (0) := Read_bank (1);
Read_bank (1) := Read_bank (2);
Read_bank (2) := Read_bank (3);
Read_bank (3) := Read_bank (4);
Read_bank (4) := Read_bank (5);
Read_bank (5) := Read_bank (6);
Read_bank (6) := Read_bank (7);
Read_bank (7) := Read_bank (8);
Read_bank (8) := "00";
-- Read Column Pipeline
Read_cols (0) := Read_cols (1);
Read_cols (1) := Read_cols (2);
Read_cols (2) := Read_cols (3);
Read_cols (3) := Read_cols (4);
Read_cols (4) := Read_cols (5);
Read_cols (5) := Read_cols (6);
Read_cols (6) := Read_cols (7);
Read_cols (7) := Read_cols (8);
Read_cols (8) := (OTHERS => '0');
-- Initialize Read command
IF Read_cmnd (0) = '1' THEN
Data_out_enable := '1';
Bank_addr := Read_bank (0);
Cols_addr := Read_cols (0);
Cols_brst := Cols_addr (2 DOWNTO 0);
Burst_counter := (OTHERS => '0');
-- Row address mux
CASE Bank_addr IS
WHEN "00" => Rows_addr := B0_row_addr;
WHEN "01" => Rows_addr := B1_row_addr;
WHEN "10" => Rows_addr := B2_row_addr;
WHEN OTHERS => Rows_addr := B3_row_addr;
END CASE;
END IF;
-- Toggle Dqs during Read command
IF Data_out_enable = '1' THEN
Dqs_int := '0';
IF Dqs_out = "00" THEN
Dqs_out <= "11";
ELSIF Dqs_out = "11" THEN
Dqs_out <= "00";
ELSE
Dqs_out <= "00";
END IF;
ELSIF Data_out_enable = '0' AND Dqs_int = '0' THEN
Dqs_out <= "ZZ";
END IF;
-- Initialize Dqs for Read command
IF Read_cmnd (2) = '1' THEN
IF Data_out_enable = '0' THEN
Dqs_int := '1';
Dqs_out <= "00";
END IF;
END IF;
-- Read Latch
IF Data_out_enable = '1' THEN
-- Initialize Memory
Init_mem (Bank_addr, CONV_INTEGER(Rows_addr));
-- Output Data
CASE Bank_addr IS
WHEN "00" => Dq <= Bank0 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "01" => Dq <= Bank1 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "10" => Dq <= Bank2 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN OTHERS => Dq <= Bank3 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
END CASE;
-- Increase Burst Counter
Burst_decode;
ELSE
Dq <= (OTHERS => 'Z');
END IF;
END IF;
--
-- Write FIFO and DM Mask Logic
--
IF Sys_clk'EVENT AND Sys_clk = '1' THEN
-- Write command pipeline
Write_cmnd (0) := Write_cmnd (1);
Write_cmnd (1) := Write_cmnd (2);
Write_cmnd (2) := '0';
-- Write command pipeline
Write_bank (0) := Write_bank (1);
Write_bank (1) := Write_bank (2);
Write_bank (2) := "00";
-- Write column pipeline
Write_cols (0) := Write_cols (1);
Write_cols (1) := Write_cols (2);
Write_cols (2) := (OTHERS => '0');
-- Initialize Write command
IF Write_cmnd (0) = '1' THEN
Data_in_enable := '1';
Bank_addr := Write_bank (0);
Cols_addr := Write_cols (0);
Cols_brst := Cols_addr (2 DOWNTO 0);
Burst_counter := (OTHERS => '0');
-- Row address mux
CASE Bank_addr IS
WHEN "00" => Rows_addr := B0_row_addr;
WHEN "01" => Rows_addr := B1_row_addr;
WHEN "10" => Rows_addr := B2_row_addr;
WHEN OTHERS => Rows_addr := B3_row_addr;
END CASE;
END IF;
-- Write data
IF Data_in_enable = '1' THEN
-- Initialize memory
Init_mem (Bank_addr, CONV_INTEGER(Rows_addr));
-- Write first data
IF Dm_pair (1) = '0' OR Dm_pair (0) = '0' THEN
-- Data Buffer
CASE Bank_addr IS
WHEN "00" => Data_buf := Bank0 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "01" => Data_buf := Bank1 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "10" => Data_buf := Bank2 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN OTHERS => Data_buf := Bank3 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
END CASE;
-- Perform DM Mask
IF Dm_pair (0) = '0' THEN
Data_buf ( 7 DOWNTO 0) := Dq_pair ( 7 DOWNTO 0);
END IF;
IF Dm_pair (1) = '0' THEN
Data_buf (15 DOWNTO 8) := Dq_pair (15 DOWNTO 8);
END IF;
-- Write Data
CASE Bank_addr IS
WHEN "00" => Bank0 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN "01" => Bank1 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN "10" => Bank2 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN OTHERS => Bank3 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
END CASE;
END IF;
-- Increase Burst Counter
Burst_decode;
-- Write second data
IF Dm_pair (3) = '0' OR Dm_pair (2) = '0' THEN
-- Data Buffer
CASE Bank_addr IS
WHEN "00" => Data_buf := Bank0 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "01" => Data_buf := Bank1 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN "10" => Data_buf := Bank2 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
WHEN OTHERS => Data_buf := Bank3 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr));
END CASE;
-- Perform DM Mask
IF Dm_pair (2) = '0' THEN
Data_buf ( 7 DOWNTO 0) := Dq_pair (23 DOWNTO 16);
END IF;
IF Dm_pair (3) = '0' THEN
Data_buf (15 DOWNTO 8) := Dq_pair (31 DOWNTO 24);
END IF;
-- Write Data
CASE Bank_addr IS
WHEN "00" => Bank0 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN "01" => Bank1 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN "10" => Bank2 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
WHEN OTHERS => Bank3 (CONV_INTEGER(Rows_addr)) (CONV_INTEGER(Cols_addr)) := Data_buf;
END CASE;
END IF;
-- Increase Burst Counter
Burst_decode;
-- tWR start and tWTR check
IF Dm_pair (3 DOWNTO 2) = "00" OR Dm_pair (1 DOWNTO 0) = "00" THEN
CASE Bank_addr IS
WHEN "00" => WR_chk0 := NOW;
WHEN "01" => WR_chk1 := NOW;
WHEN "10" => WR_chk2 := NOW;
WHEN OTHERS => WR_chk3 := NOW;
END CASE;
-- tWTR check
ASSERT (Read_enable = '0')
REPORT "tWTR violation during Read"
SEVERITY WARNING;
END IF;
END IF;
END IF;
--
-- Auto Precharge Calculation
--
IF Sys_clk'EVENT AND Sys_clk = '1' THEN
-- Precharge counter
IF Read_precharge (0) = '1' OR Write_precharge (0) = '1' THEN
Count_precharge (0) := Count_precharge (0) + 1;
END IF;
IF Read_precharge (1) = '1' OR Write_precharge (1) = '1' THEN
Count_precharge (1) := Count_precharge (1) + 1;
END IF;
IF Read_precharge (2) = '1' OR Write_precharge (2) = '1' THEN
Count_precharge (2) := Count_precharge (2) + 1;
END IF;
IF Read_precharge (3) = '1' OR Write_precharge (3) = '1' THEN
Count_precharge (3) := Count_precharge (3) + 1;
END IF;
-- Read with AutoPrecharge Calculation
-- The device start internal precharge when:
-- 1. Meet tRAS requirement
-- 2. BL/2 cycles after command
IF ((Read_precharge(0) = '1') AND (NOW - RAS_chk0 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge(0) >= 1) OR
(Burst_length_4 = '1' AND Count_precharge(0) >= 2) OR
(Burst_length_8 = '1' AND Count_precharge(0) >= 4)) THEN
Pc_b0 := '1';
Act_b0 := '0';
RP_chk0 := NOW;
Read_precharge(0) := '0';
END IF;
END IF;
IF ((Read_precharge(1) = '1') AND (NOW - RAS_chk1 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge(1) >= 1) OR
(Burst_length_4 = '1' AND Count_precharge(1) >= 2) OR
(Burst_length_8 = '1' AND Count_precharge(1) >= 4)) THEN
Pc_b1 := '1';
Act_b1 := '0';
RP_chk1 := NOW;
Read_precharge(1) := '0';
END IF;
END IF;
IF ((Read_precharge(2) = '1') AND (NOW - RAS_chk2 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge(2) >= 1) OR
(Burst_length_4 = '1' AND Count_precharge(2) >= 2) OR
(Burst_length_8 = '1' AND Count_precharge(2) >= 4)) THEN
Pc_b2 := '1';
Act_b2 := '0';
RP_chk2 := NOW;
Read_precharge(2) := '0';
END IF;
END IF;
IF ((Read_precharge(3) = '1') AND (NOW - RAS_chk3 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge(3) >= 1) OR
(Burst_length_4 = '1' AND Count_precharge(3) >= 2) OR
(Burst_length_8 = '1' AND Count_precharge(3) >= 4)) THEN
Pc_b3 := '1';
Act_b3 := '0';
RP_chk3 := NOW;
Read_precharge(3) := '0';
END IF;
END IF;
-- Write with AutoPrecharge Calculation
-- The device start internal precharge when:
-- 1. Meet tRAS requirement
-- 2. Two clock after last burst
-- Since tWR is time base, the model will compensate tRP
IF ((Write_precharge(0) = '1') AND (NOW - RAS_chk0 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge (0) >= 4) OR
(Burst_length_4 = '1' AND Count_precharge (0) >= 5) OR
(Burst_length_8 = '1' AND Count_precharge (0) >= 7)) THEN
Pc_b0 := '1';
Act_b0 := '0';
RP_chk0 := NOW - ((2 * tCK) - tWR);
Write_precharge(0) := '0';
END IF;
END IF;
IF ((Write_precharge(1) = '1') AND (NOW - RAS_chk1 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge (1) >= 4) OR
(Burst_length_4 = '1' AND Count_precharge (1) >= 5) OR
(Burst_length_8 = '1' AND Count_precharge (1) >= 7)) THEN
Pc_b1 := '1';
Act_b1 := '0';
RP_chk1 := NOW - ((2 * tCK) - tWR);
Write_precharge(1) := '0';
END IF;
END IF;
IF ((Write_precharge(2) = '1') AND (NOW - RAS_chk2 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge (2) >= 4) OR
(Burst_length_4 = '1' AND Count_precharge (2) >= 5) OR
(Burst_length_8 = '1' AND Count_precharge (2) >= 7)) THEN
Pc_b2 := '1';
Act_b2 := '0';
RP_chk2 := NOW - ((2 * tCK) - tWR);
Write_precharge(2) := '0';
END IF;
END IF;
IF ((Write_precharge(3) = '1') AND (NOW - RAS_chk3 >= tRAS)) THEN
IF ((Burst_length_2 = '1' AND Count_precharge (3) >= 4) OR
(Burst_length_4 = '1' AND Count_precharge (3) >= 5) OR
(Burst_length_8 = '1' AND Count_precharge (3) >= 7)) THEN
Pc_b3 := '1';
Act_b3 := '0';
RP_chk3 := NOW - ((2 * tCK) - tWR);
Write_precharge(3) := '0';
END IF;
END IF;
END IF;
--
-- DLL Counter
--
IF Sys_clk'EVENT AND Sys_clk = '1' THEN
IF (DLL_Reset = '1' AND DLL_done = '0') THEN
DLL_count := DLL_count + 1;
IF (DLL_count >= 200) THEN
DLL_done := '1';
END IF;
END IF;
END IF;
--
-- Control Logic
--
IF Sys_clk'EVENT AND Sys_clk = '1' THEN
-- Auto Refresh
IF Aref_enable = '1' THEN
-- Auto Refresh to Auto Refresh
ASSERT (NOW - RFC_chk >= tRFC)
REPORT "tRFC violation during Auto Refresh"
SEVERITY WARNING;
-- Precharge to Auto Refresh
ASSERT ((NOW - RP_chk0 >= tRP) AND (NOW - RP_chk1 >= tRP) AND
(NOW - RP_chk2 >= tRP) AND (NOW - RP_chk3 >= tRP))
REPORT "tRP violation during Auto Refresh"
SEVERITY WARNING;
-- Precharge to Auto Refresh
ASSERT (Pc_b0 = '1' AND Pc_b1 = '1' AND Pc_b2 = '1' AND Pc_b3 = '1')
REPORT "All banks must be Precharge before Auto Refresh"
SEVERITY WARNING;
-- Record current tRFC time
RFC_chk := NOW;
END IF;
-- Extended Load Mode Register
IF Ext_mode_enable = '1' THEN
IF (Pc_b0 = '1' AND Pc_b1 = '1' AND Pc_b2 = '1' AND Pc_b3 = '1') THEN
IF (Addr (0) = '0') THEN
DLL_enable := '1';
ELSE
DLL_enable := '0';
END IF;
END IF;
-- Precharge to EMR
ASSERT (Pc_b0 = '1' AND Pc_b1 = '1' AND Pc_b2 = '1' AND Pc_b3 = '1')
REPORT "All bank must be Precharged before Extended Mode Register"
SEVERITY WARNING;
-- Precharge to EMR
ASSERT ((NOW - RP_chk0 >= tRP) AND (NOW - RP_chk1 >= tRP) AND
(NOW - RP_chk2 >= tRP) AND (NOW - RP_chk3 >= tRP))
REPORT "tRP violation during Extended Load Register"
SEVERITY WARNING;
-- LMR/EMR to EMR
ASSERT (NOW - MRD_chk >= tMRD)
REPORT "tMRD violation during Extended Mode Register"
SEVERITY WARNING;
-- Record current tMRD time
MRD_chk := NOW;
END IF;
-- Load Mode Register
IF Mode_reg_enable = '1' THEN
-- Register mode
Mode_reg <= Addr;
-- DLL Reset
IF (DLL_enable = '1' AND Addr (8) = '1') THEN
DLL_reset := '1';
DLL_done := '0';
DLL_count := 0;
ELSIF (DLL_enable = '1' AND DLL_reset = '0' AND Addr (8) = '0') THEN
ASSERT (FALSE)
REPORT "DLL is ENABLE: DLL RESET is require"
SEVERITY WARNING;
ELSIF (DLL_enable = '0' AND Addr (8) = '1') THEN
ASSERT (FALSE)
REPORT "DLL is DISABLE: DLL RESET will be ignored"
SEVERITY WARNING;
END IF;
-- Precharge to LMR
ASSERT (Pc_b0 = '1' AND Pc_b1 = '1' AND Pc_b2 = '1' AND Pc_b3 = '1')
REPORT "All bank must be Precharged before Load Mode Register"
SEVERITY WARNING;
-- Precharge to EMR
ASSERT ((NOW - RP_chk0 >= tRP) AND (NOW - RP_chk1 >= tRP) AND
(NOW - RP_chk2 >= tRP) AND (NOW - RP_chk3 >= tRP))
REPORT "tRP violation during Load Mode Register"
SEVERITY WARNING;
-- LMR/ELMR to LMR
ASSERT (NOW - MRD_chk >= tMRD)
REPORT "tMRD violation during Load Mode Register"
SEVERITY WARNING;
-- Check for invalid Burst Length
ASSERT ((Addr (2 DOWNTO 0) = "001") OR -- BL = 2
(Addr (2 DOWNTO 0) = "010") OR -- BL = 4
(Addr (2 DOWNTO 0) = "011")) -- BL = 8
REPORT "Invalid Burst Length during Load Mode Register"
SEVERITY WARNING;
-- Check for invalid CAS Latency
ASSERT ((Addr (6 DOWNTO 4) = "010") OR -- CL = 2.0
(Addr (6 DOWNTO 4) = "110")) -- CL = 2.5
REPORT "Invalid CAS Latency during Load Mode Register"
SEVERITY WARNING;
-- Record current tMRD time
MRD_chk := NOW;
END IF;
-- Active Block (latch Bank and Row Address)
IF Active_enable = '1' THEN
-- Activate an OPEN bank can corrupt data
ASSERT ((Ba = "00" AND Act_b0 = '0') OR
(Ba = "01" AND Act_b1 = '0') OR
(Ba = "10" AND Act_b2 = '0') OR
(Ba = "11" AND Act_b3 = '0'))
REPORT "Bank is already activated - data can be corrupted"
SEVERITY WARNING;
-- Activate Bank 0
IF Ba = "00" AND Pc_b0 = '1' THEN
-- Activate to Activate (same bank)
ASSERT (NOW - RC_chk0 >= tRC)
REPORT "tRC violation during Activate Bank 0"
SEVERITY WARNING;
-- Precharge to Active
ASSERT (NOW - RP_chk0 >= tRP)
REPORT "tRP violation during Activate Bank 0"
SEVERITY WARNING;
-- Record Variables for checking violation
Act_b0 := '1';
Pc_b0 := '0';
B0_row_addr := Addr;
RC_chk0 := NOW;
RCD_chk0 := NOW;
RAS_chk0 := NOW;
RAP_chk0 := NOW;
END IF;
-- Activate Bank 1
IF Ba = "01" AND Pc_b1 = '1' THEN
-- Activate to Activate (same bank)
ASSERT (NOW - RC_chk1 >= tRC)
REPORT "tRC violation during Activate Bank 1"
SEVERITY WARNING;
-- Precharge to Active
ASSERT (NOW - RP_chk1 >= tRP)
REPORT "tRP violation during Activate Bank 1"
SEVERITY WARNING;
-- Record Variables for checking violation
Act_b1 := '1';
Pc_b1 := '0';
B1_row_addr := Addr;
RC_chk1 := NOW;
RCD_chk1 := NOW;
RAS_chk1 := NOW;
RAP_chk1 := NOW;
END IF;
-- Activate Bank 2
IF Ba = "10" AND Pc_b2 = '1' THEN
-- Activate to Activate (same bank)
ASSERT (NOW - RC_chk2 >= tRC)
REPORT "tRC violation during Activate Bank 2"
SEVERITY WARNING;
-- Precharge to Active
ASSERT (NOW - RP_chk2 >= tRP)
REPORT "tRP violation during Activate Bank 2"
SEVERITY WARNING;
-- Record Variables for checking violation
Act_b2 := '1';
Pc_b2 := '0';
B2_row_addr := Addr;
RC_chk2 := NOW;
RCD_chk2 := NOW;
RAS_chk2 := NOW;
RAP_chk2 := NOW;
END IF;
-- Activate Bank 3
IF Ba = "11" AND Pc_b3 = '1' THEN
-- Activate to Activate (same bank)
ASSERT (NOW - RC_chk3 >= tRC)
REPORT "tRC violation during Activate Bank 3"
SEVERITY WARNING;
-- Precharge to Active
ASSERT (NOW - RP_chk3 >= tRP)
REPORT "tRP violation during Activate Bank 3"
SEVERITY WARNING;
-- Record Variables for checking violation
Act_b3 := '1';
Pc_b3 := '0';
B3_row_addr := Addr;
RC_chk3 := NOW;
RCD_chk3 := NOW;
RAS_chk3 := NOW;
RAP_chk3 := NOW;
END IF;
-- Activate Bank A to Activate Bank B
IF (Prev_bank /= Ba) THEN
ASSERT (NOW - RRD_chk >= tRRD)
REPORT "tRRD violation during Activate"
SEVERITY WARNING;
END IF;
-- AutoRefresh to Activate
ASSERT (NOW - RFC_chk >= tRFC)
REPORT "tRFC violation during Activate"
SEVERITY WARNING;
-- Record Variables for Checking Violation
RRD_chk := NOW;
Prev_bank := Ba;
END IF;
-- Precharge Block - Consider NOP if bank already precharged or in process of precharging
IF Prech_enable = '1' THEN
-- EMR or LMR to Precharge
ASSERT (NOW - MRD_chk >= tMRD)
REPORT "tMRD violation during Precharge"
SEVERITY WARNING;
-- Precharge Bank 0
IF ((Addr (10) = '1' OR (Addr (10) = '0' AND Ba = "00")) AND Act_b0 = '1') THEN
Act_b0 := '0';
Pc_b0 := '1';
RP_chk0 := NOW;
-- Activate to Precharge bank 0
ASSERT (NOW - RAS_chk0 >= tRAS)
REPORT "tRAS violation during Precharge"
SEVERITY WARNING;
-- tWR violation check for Write
ASSERT (NOW - WR_chk0 >= tWR)
REPORT "tWR violation during Precharge"
SEVERITY WARNING;
END IF;
-- Precharge Bank 1
IF ((Addr (10) = '1' OR (Addr (10) = '0' AND Ba = "01")) AND Act_b1 = '1') THEN
Act_b1 := '0';
Pc_b1 := '1';
RP_chk1 := NOW;
-- Activate to Precharge
ASSERT (NOW - RAS_chk1 >= tRAS)
REPORT "tRAS violation during Precharge"
SEVERITY WARNING;
-- tWR violation check for Write
ASSERT (NOW - WR_chk1 >= tWR)
REPORT "tWR violation during Precharge"
SEVERITY WARNING;
END IF;
-- Precharge Bank 2
IF ((Addr (10) = '1' OR (Addr (10) = '0' AND Ba = "10")) AND Act_b2 = '1') THEN
Act_b2 := '0';
Pc_b2 := '1';
RP_chk2 := NOW;
-- Activate to Precharge
ASSERT (NOW - RAS_chk2 >= tRAS)
REPORT "tRAS violation during Precharge"
SEVERITY WARNING;
-- tWR violation check for Write
ASSERT (NOW - WR_chk2 >= tWR)
REPORT "tWR violation during Precharge"
SEVERITY WARNING;
END IF;
-- Precharge Bank 3
IF ((Addr (10) = '1' OR (Addr (10) = '0' AND Ba = "11")) AND Act_b3 = '1') THEN
Act_b3 := '0';
Pc_b3 := '1';
RP_chk3 := NOW;
-- Activate to Precharge
ASSERT (NOW - RAS_chk3 >= tRAS)
REPORT "tRAS violation during Precharge"
SEVERITY WARNING;
-- tWR violation check for Write
ASSERT (NOW - WR_chk3 >= tWR)
REPORT "tWR violation during Precharge"
SEVERITY WARNING;
END IF;
-- Pipeline for READ
IF CAS_latency_15 = '1' THEN
A10_precharge (3) := Addr(10);
Bank_precharge (3) := Ba;
Cmnd_precharge (3) := '1';
ELSIF CAS_latency_2 = '1' THEN
A10_precharge (4) := Addr(10);
Bank_precharge (4) := Ba;
Cmnd_precharge (4) := '1';
ELSIF CAS_latency_25 = '1' THEN
A10_precharge (5) := Addr(10);
Bank_precharge (5) := Ba;
Cmnd_precharge (5) := '1';
ELSIF CAS_latency_3 = '1' THEN
A10_precharge (6) := Addr(10);
Bank_precharge (6) := Ba;
Cmnd_precharge (6) := '1';
ELSIF CAS_latency_4 = '1' THEN
A10_precharge (8) := Addr(10);
Bank_precharge (8) := Ba;
Cmnd_precharge (8) := '1';
END IF;
END IF;
-- Burst Terminate
IF Burst_term = '1' THEN
-- Pipeline for Read
IF CAS_latency_15 = '1' THEN
Cmnd_bst (3) := '1';
ELSIF CAS_latency_2 = '1' THEN
Cmnd_bst (4) := '1';
ELSIF CAS_latency_25 = '1' THEN
Cmnd_bst (5) := '1';
ELSIF CAS_latency_3 = '1' THEN
Cmnd_bst (6) := '1';
ELSIF CAS_latency_4 = '1' THEN
Cmnd_bst (8) := '1';
END IF;
-- Terminate Write
ASSERT (Data_in_enable = '0')
REPORT "It's illegal to Burst Terminate a Write"
SEVERITY WARNING;
-- Terminate Read with Auto Precharge
ASSERT (Read_precharge (0) = '0' AND Read_precharge (1) = '0' AND
Read_precharge (2) = '0' AND Read_precharge (3) = '0')
REPORT "It's illegal to Burst Terminate a Read with Auto Precharge"
SEVERITY WARNING;
END IF;
-- Read Command
IF Read_enable = '1' THEN
-- CAS Latency Pipeline
IF Cas_latency_15 = '1' THEN
Read_cmnd (3) := '1';
Read_bank (3) := Ba;
Read_cols (3) := Addr (8 DOWNTO 0);
ELSIF Cas_latency_2 = '1' THEN
Read_cmnd (4) := '1';
Read_bank (4) := Ba;
Read_cols (4) := Addr (8 DOWNTO 0);
ELSIF Cas_latency_25 = '1' THEN
Read_cmnd (5) := '1';
Read_bank (5) := Ba;
Read_cols (5) := Addr (8 DOWNTO 0);
ELSIF Cas_latency_3 = '1' THEN
Read_cmnd (6) := '1';
Read_bank (6) := Ba;
Read_cols (6) := Addr (8 DOWNTO 0);
ELSIF Cas_latency_4 = '1' THEN
Read_cmnd (8) := '1';
Read_bank (8) := Ba;
Read_cols (8) := Addr (8 DOWNTO 0);
END IF;
-- Write to Read: Terminate Write Immediately
IF Data_in_enable = '1' THEN
Data_in_enable := '0';
END IF;
-- Interrupting a Read with Auto Precharge (same bank only)
ASSERT (Read_precharge(CONV_INTEGER(Ba)) = '0')
REPORT "It's illegal to interrupt a Read with Auto Precharge"
SEVERITY WARNING;
-- Activate to Read
ASSERT ((Ba = "00" AND Act_b0 = '1') OR
(Ba = "01" AND Act_b1 = '1') OR
(Ba = "10" AND Act_b2 = '1') OR
(Ba = "11" AND Act_b3 = '1'))
REPORT "Bank is not Activated for Read"
SEVERITY WARNING;
-- Activate to Read without Auto Precharge
IF Addr (10) = '0' THEN
ASSERT ((Ba = "00" AND NOW - RCD_chk0 >= tRCD) OR
(Ba = "01" AND NOW - RCD_chk1 >= tRCD) OR
(Ba = "10" AND NOW - RCD_chk2 >= tRCD) OR
(Ba = "11" AND NOW - RCD_chk3 >= tRCD))
REPORT "tRCD violation during Read"
SEVERITY WARNING;
END IF;
-- Activate to Read with Auto Precharge
IF Addr (10) = '1' THEN
ASSERT ((Ba = "00" AND NOW - RAP_chk0 >= tRAP) OR
(Ba = "01" AND NOW - RAP_chk1 >= tRAP) OR
(Ba = "10" AND NOW - RAP_chk2 >= tRAP) OR
(Ba = "11" AND NOW - RAP_chk3 >= tRAP))
REPORT "tRAP violation during Read"
SEVERITY WARNING;
END IF;
-- Auto precharge
IF Addr (10) = '1' THEN
Read_precharge (Conv_INTEGER(Ba)) := '1';
Count_precharge (Conv_INTEGER(Ba)) := 0;
END IF;
-- DLL Check
IF (DLL_reset = '1') THEN
ASSERT (DLL_done = '1')
REPORT "DLL RESET not complete"
SEVERITY WARNING;
END IF;
END IF;
-- Write Command
IF Write_enable = '1' THEN
-- Pipeline for Write
Write_cmnd (2) := '1';
Write_bank (2) := Ba;
Write_cols (2) := Addr (8 DOWNTO 0);
-- Interrupting a Write with Auto Precharge (same bank only)
ASSERT (Write_precharge(CONV_INTEGER(Ba)) = '0')
REPORT "It's illegal to interrupt a Write with Auto Precharge"
SEVERITY WARNING;
-- Activate to Write
ASSERT ((Ba = "00" AND Act_b0 = '1') OR
(Ba = "01" AND Act_b1 = '1') OR
(Ba = "10" AND Act_b2 = '1') OR
(Ba = "11" AND Act_b3 = '1'))
REPORT "Bank is not Activated for Write"
SEVERITY WARNING;
-- Activate to Write
ASSERT ((Ba = "00" AND NOW - RCD_chk0 >= tRCD) OR
(Ba = "01" AND NOW - RCD_chk1 >= tRCD) OR
(Ba = "10" AND NOW - RCD_chk2 >= tRCD) OR
(Ba = "11" AND NOW - RCD_chk3 >= tRCD))
REPORT "tRCD violation during Write"
SEVERITY WARNING;
-- Auto precharge
IF Addr (10) = '1' THEN
Write_precharge (Conv_INTEGER(Ba)) := '1';
Count_precharge (Conv_INTEGER(Ba)) := 0;
END IF;
END IF;
END IF;
END PROCESS;
--
-- Dqs Receiver
--
dqs_rcvrs : PROCESS
VARIABLE Dm_temp : STD_LOGIC_VECTOR (1 DOWNTO 0);
VARIABLE Dq_temp : STD_LOGIC_VECTOR (data_bits - 1 DOWNTO 0);
BEGIN
WAIT ON Dqs;
-- Latch data at posedge Dqs
IF Dqs'EVENT AND Dqs (1) = '1' AND Dqs (0) = '1' THEN
Dq_temp := Dq;
Dm_temp := Dm;
END IF;
-- Latch data at negedge Dqs
IF Dqs'EVENT AND Dqs (1) = '0' AND Dqs (0) = '0' THEN
Dq_pair <= (Dq & Dq_temp);
Dm_pair <= (Dm & Dm_temp);
END IF;
END PROCESS;
--
-- Setup timing checks
--
Setup_check : PROCESS
BEGIN
WAIT ON Sys_clk;
IF Sys_clk'EVENT AND Sys_clk = '1' THEN
ASSERT(Cke'LAST_EVENT >= tIS)
REPORT "CKE Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(Cs_n'LAST_EVENT >= tIS)
REPORT "CS# Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(Cas_n'LAST_EVENT >= tIS)
REPORT "CAS# Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(Ras_n'LAST_EVENT >= tIS)
REPORT "RAS# Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(We_n'LAST_EVENT >= tIS)
REPORT "WE# Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(Addr'LAST_EVENT >= tIS)
REPORT "ADDR Setup time violation -- tIS"
SEVERITY WARNING;
ASSERT(Ba'LAST_EVENT >= tIS)
REPORT "BA Setup time violation -- tIS"
SEVERITY WARNING;
END IF;
END PROCESS;
--
-- Hold timing checks
--
Hold_check : PROCESS
BEGIN
WAIT ON Sys_clk'DELAYED (tIH);
IF Sys_clk'DELAYED (tIH) = '1' THEN
ASSERT(Cke'LAST_EVENT >= tIH)
REPORT "CKE Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(Cs_n'LAST_EVENT >= tIH)
REPORT "CS# Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(Cas_n'LAST_EVENT >= tIH)
REPORT "CAS# Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(Ras_n'LAST_EVENT >= tIH)
REPORT "RAS# Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(We_n'LAST_EVENT >= tIH)
REPORT "WE# Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(Addr'LAST_EVENT >= tIH)
REPORT "ADDR Hold time violation -- tIH"
SEVERITY WARNING;
ASSERT(Ba'LAST_EVENT >= tIH)
REPORT "BA Hold time violation -- tIH"
SEVERITY WARNING;
END IF;
END PROCESS;
END behave;
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