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[/] [sdr_ctrl/] [trunk/] [rtl/] [core/] [sdrc_xfr_ctl.v] - Rev 18
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/********************************************************************* SDRAM Controller Transfer control This file is part of the sdram controller project http://www.opencores.org/cores/sdr_ctrl/ Description: SDRAM Controller Transfer control This module takes requests from sdrc_bank_ctl and runs the transfer. The input request is guaranteed to be in a bank that is precharged and activated. This block runs the transfer until a burst boundary is reached, then issues another read/write command to sequentially step thru memory if wrap=0, until the transfer is completed. if a read transfer finishes and the caddr is not at a burst boundary a burst terminate command is issued unless another read/write or precharge to the same bank is pending. if a write transfer finishes and the caddr is not at a burst boundary a burst terminate command is issued unless a read/write is pending. If a refresh request is made, the bank_ctl will be held off until the number of refreshes requested are completed. This block also handles SDRAM initialization. To Do: nothing Author(s): - Dinesh Annayya, dinesha@opencores.org Version : 1.0 - 8th Jan 2012 Copyright (C) 2000 Authors and OPENCORES.ORG This source file may be used and distributed without restriction provided that this copyright statement is not removed from the file and that any derivative work contains the original copyright notice and the associated disclaimer. This source file is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This source is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this source; if not, download it from http://www.opencores.org/lgpl.shtml *******************************************************************/ `include "sdrc.def" module sdrc_xfr_ctl (clk, reset_n, /* Transfer request from bank_ctl */ r2x_idle, // Req is idle b2x_idle, // All banks are idle b2x_req, // Req from bank_ctl b2x_start, // first chunk of transfer b2x_last, // last chunk of transfer b2x_id, // Transfer ID b2x_ba, // bank address b2x_addr, // row/col address b2x_len, // transfer length b2x_cmd, // transfer command b2x_wrap, // Wrap mode transfer x2b_ack, // command accepted /* Status to bank_ctl, req_gen */ b2x_tras_ok, // Tras for all banks expired x2b_refresh, // We did a refresh x2b_pre_ok, // OK to do a precharge (per bank) x2b_act_ok, // OK to do an activate x2b_rdok, // OK to do a read x2b_wrok, // OK to do a write /* SDRAM I/O */ sdr_cs_n, sdr_cke, sdr_ras_n, sdr_cas_n, sdr_we_n, sdr_dqm, sdr_ba, sdr_addr, sdr_din, sdr_dout, sdr_den_n, /* Data Flow to the app */ x2a_rdstart, x2a_wrstart, x2a_rdlast, x2a_wrlast, x2a_id, app_wrdt, app_wren_n, x2a_wrnext, x2a_rddt, x2a_rdok, sdr_init_done, /* SDRAM Parameters */ sdram_enable, sdram_mode_reg, /* output for generate row address of the transfer */ xfr_bank_sel, /* SDRAM Timing */ cas_latency, trp_delay, // Precharge to refresh delay trcar_delay, // Auto-refresh period twr_delay, // Write recovery delay rfsh_time, // time per row (31.25 or 15.6125 uS) rfsh_rmax); // Number of rows to rfsh at a time (<120uS) parameter APP_AW = 30; // Application Address Width parameter APP_DW = 32; // Application Data Width parameter APP_BW = 4; // Application Byte Width parameter APP_RW = 9; // Application Request Width parameter SDR_DW = 16; // SDR Data Width parameter SDR_BW = 2; // SDR Byte Width input clk, reset_n; /* Req from bank_ctl */ input b2x_req, b2x_start, b2x_last, b2x_tras_ok, b2x_wrap, r2x_idle, b2x_idle; input [`SDR_REQ_ID_W-1:0] b2x_id; input [1:0] b2x_ba; input [11:0] b2x_addr; input [APP_RW-1:0] b2x_len; input [1:0] b2x_cmd; output x2b_ack; /* Status to bank_ctl */ output [3:0] x2b_pre_ok; output x2b_refresh, x2b_act_ok, x2b_rdok, x2b_wrok; /* Data Flow to the app */ output x2a_rdstart, x2a_wrstart, x2a_rdlast, x2a_wrlast; output [`SDR_REQ_ID_W-1:0] x2a_id; input [SDR_DW-1:0] app_wrdt; input [SDR_BW-1:0] app_wren_n; output [SDR_DW-1:0] x2a_rddt; output x2a_wrnext, x2a_rdok, sdr_init_done; /* Interface to SDRAMs */ output sdr_cs_n, sdr_cke, sdr_ras_n, sdr_cas_n, sdr_we_n; output [SDR_BW-1:0] sdr_dqm; output [1:0] sdr_ba; output [11:0] sdr_addr; input [SDR_DW-1:0] sdr_din; output [SDR_DW-1:0] sdr_dout; output [SDR_BW-1:0] sdr_den_n; output [1:0] xfr_bank_sel; input sdram_enable; input [11:0] sdram_mode_reg; input [2:0] cas_latency; input [3:0] trp_delay, trcar_delay, twr_delay; input [`SDR_RFSH_TIMER_W-1 : 0] rfsh_time; input [`SDR_RFSH_ROW_CNT_W-1:0] rfsh_rmax; /************************************************************************/ // Internal Nets `define XFR_IDLE 2'b00 `define XFR_WRITE 2'b01 `define XFR_READ 2'b10 `define XFR_RDWT 2'b11 reg [1:0] xfr_st, next_xfr_st; reg [11:0] xfr_caddr; wire last_burst; wire x2a_rdstart, x2a_wrstart, x2a_rdlast, x2a_wrlast; reg l_start, l_last, l_wrap; wire [`SDR_REQ_ID_W-1:0] x2a_id; reg [`SDR_REQ_ID_W-1:0] l_id; wire [1:0] xfr_ba; reg [1:0] l_ba; wire [11:0] xfr_addr; wire [APP_RW-1:0] xfr_len, next_xfr_len; reg [APP_RW-1:0] l_len; reg mgmt_idle, mgmt_req; reg [3:0] mgmt_cmd; reg [11:0] mgmt_addr; reg [1:0] mgmt_ba; reg sel_mgmt, sel_b2x; reg cb_pre_ok, rdok, wrok, wr_next, rd_next, sdr_init_done, act_cmd, d_act_cmd; wire [3:0] b2x_sdr_cmd, xfr_cmd; reg [3:0] i_xfr_cmd; wire mgmt_ack, x2b_ack, b2x_read, b2x_write, b2x_prechg, d_rd_next, dt_next, xfr_end, rd_pipe_mt, ld_xfr, rd_last, d_rd_last, wr_last, l_xfr_end, rd_start, d_rd_start, wr_start, page_hit, burst_bdry, xfr_wrap, b2x_prechg_hit; reg [4:0] l_rd_next, l_rd_start, l_rd_last; assign b2x_read = (b2x_cmd == `OP_RD) ? 1'b1 : 1'b0; assign b2x_write = (b2x_cmd == `OP_WR) ? 1'b1 : 1'b0; assign b2x_prechg = (b2x_cmd == `OP_PRE) ? 1'b1 : 1'b0; assign b2x_sdr_cmd = (b2x_cmd == `OP_PRE) ? `SDR_PRECHARGE : (b2x_cmd == `OP_ACT) ? `SDR_ACTIVATE : (b2x_cmd == `OP_RD) ? `SDR_READ : (b2x_cmd == `OP_WR) ? `SDR_WRITE : `SDR_DESEL; assign page_hit = (b2x_ba == l_ba) ? 1'b1 : 1'b0; assign b2x_prechg_hit = b2x_prechg & page_hit; assign xfr_cmd = (sel_mgmt) ? mgmt_cmd : (sel_b2x) ? b2x_sdr_cmd : i_xfr_cmd; assign xfr_addr = (sel_mgmt) ? mgmt_addr : (sel_b2x) ? b2x_addr : xfr_caddr; assign mgmt_ack = sel_mgmt; assign x2b_ack = sel_b2x; assign ld_xfr = sel_b2x & (b2x_read | b2x_write); assign xfr_len = (ld_xfr) ? b2x_len : l_len; assign next_xfr_len = (xfr_end) ? xfr_len : xfr_len - 1; assign d_rd_next = (cas_latency == 2'b01) ? l_rd_next[2] : (cas_latency == 2'b10) ? l_rd_next[3] : l_rd_next[4]; assign d_rd_last = (cas_latency == 2'b01) ? l_rd_last[2] : (cas_latency == 2'b10) ? l_rd_last[3] : l_rd_last[4]; assign d_rd_start = (cas_latency == 2'b01) ? l_rd_start[2] : (cas_latency == 2'b10) ? l_rd_start[3] : l_rd_start[4]; assign rd_pipe_mt = (cas_latency == 2'b01) ? ~|l_rd_next[1:0] : (cas_latency == 2'b10) ? ~|l_rd_next[2:0] : ~|l_rd_next[3:0]; assign dt_next = wr_next | d_rd_next; assign xfr_end = ~|xfr_len; assign l_xfr_end = ~|l_len; assign rd_start = ld_xfr & b2x_read & b2x_start; assign wr_start = ld_xfr & b2x_write & b2x_start; assign rd_last = rd_next & last_burst & ~|xfr_len[APP_RW-1:1]; //assign wr_last = wr_next & last_burst & ~|xfr_len[APP_RW-1:1]; assign wr_last = last_burst & ~|xfr_len[APP_RW-1:1]; //assign xfr_ba = (ld_xfr) ? b2x_ba : l_ba; assign xfr_ba = (sel_mgmt) ? mgmt_ba : (sel_b2x) ? b2x_ba : l_ba; assign xfr_wrap = (ld_xfr) ? b2x_wrap : l_wrap; // assign burst_bdry = ~|xfr_caddr[2:0]; assign burst_bdry = ~|xfr_caddr[1:0]; always @ (posedge clk) begin if (~reset_n) begin xfr_caddr <= 12'b0; l_start <= 1'b0; l_last <= 1'b0; l_wrap <= 1'b0; l_id <= 0; l_ba <= 0; l_len <= 0; l_rd_next <= 5'b0; l_rd_start <= 5'b0; l_rd_last <= 5'b0; act_cmd <= 1'b0; d_act_cmd <= 1'b0; xfr_st <= `XFR_IDLE; end // if (~reset_n) else begin xfr_caddr <= (ld_xfr) ? b2x_addr + 12'h1 : (rd_next | wr_next) ? xfr_caddr + 12'h1 : xfr_caddr; l_start <= (dt_next) ? 1'b0 : (ld_xfr) ? b2x_start : l_start; l_last <= (ld_xfr) ? b2x_last : l_last; l_wrap <= (ld_xfr) ? b2x_wrap : l_wrap; l_id <= (ld_xfr) ? b2x_id : l_id; l_ba <= (ld_xfr) ? b2x_ba : l_ba; l_len <= next_xfr_len; l_rd_next <= {l_rd_next[3:0], rd_next}; l_rd_start <= {l_rd_start[3:0], rd_start}; l_rd_last <= {l_rd_last[3:0], rd_last}; act_cmd <= (xfr_cmd == `SDR_ACTIVATE) ? 1'b1 : 1'b0; d_act_cmd <= act_cmd; xfr_st <= next_xfr_st; end // else: !if(~reset_n) end // always @ (posedge clk) always @ (*) begin case (xfr_st) `XFR_IDLE : begin sel_mgmt = mgmt_req; sel_b2x = ~mgmt_req & sdr_init_done & b2x_req; i_xfr_cmd = `SDR_DESEL; rd_next = ~mgmt_req & sdr_init_done & b2x_req & b2x_read; wr_next = ~mgmt_req & sdr_init_done & b2x_req & b2x_write; rdok = ~mgmt_req; cb_pre_ok = 1'b1; wrok = ~mgmt_req; next_xfr_st = (mgmt_req | ~sdr_init_done) ? `XFR_IDLE : (~b2x_req) ? `XFR_IDLE : (b2x_read) ? `XFR_READ : (b2x_write) ? `XFR_WRITE : `XFR_IDLE; end // case: `XFR_IDLE `XFR_READ : begin rd_next = ~l_xfr_end | l_xfr_end & ~mgmt_req & b2x_req & b2x_read; wr_next = 1'b0; rdok = l_xfr_end & ~mgmt_req; cb_pre_ok = l_xfr_end; wrok = 1'b0; sel_mgmt = 1'b0; if (l_xfr_end) begin // end of transfer if (~l_wrap) begin // Current transfer was not wrap mode, may need BT // If next cmd is a R or W or PRE to same bank allow // it else issue BT // This is a little pessimistic since BT is issued // for non-wrap mode transfers even if the transfer // ends on a burst boundary, but is felt to be of // minimal performance impact. i_xfr_cmd = `SDR_BT; sel_b2x = b2x_req & ~mgmt_req & (b2x_read | b2x_prechg_hit); end // if (~l_wrap) else begin // Wrap mode transfer, by definition is end of burst // boundary i_xfr_cmd = `SDR_DESEL; sel_b2x = b2x_req & ~mgmt_req & ~b2x_write; end // else: !if(~l_wrap) next_xfr_st = (sdr_init_done) ? ((b2x_req & ~mgmt_req & b2x_read) ? `XFR_READ : `XFR_RDWT) : `XFR_IDLE; end // if (l_xfr_end) else begin // Not end of transfer // If current transfer was not wrap mode and we are at // the start of a burst boundary issue another R cmd to // step sequemtially thru memory, ELSE, // issue precharge/activate commands from the bank control i_xfr_cmd = (burst_bdry & ~l_wrap) ? `SDR_READ : `SDR_DESEL; sel_b2x = ~(burst_bdry & ~l_wrap) & b2x_req; next_xfr_st = `XFR_READ; end // else: !if(l_xfr_end) end // case: `XFR_READ `XFR_RDWT : begin rd_next = ~mgmt_req & b2x_req & b2x_read; wr_next = rd_pipe_mt & ~mgmt_req & b2x_req & b2x_write; rdok = ~mgmt_req; cb_pre_ok = 1'b1; wrok = rd_pipe_mt & ~mgmt_req; sel_mgmt = mgmt_req; sel_b2x = ~mgmt_req & b2x_req; i_xfr_cmd = `SDR_DESEL; next_xfr_st = (~mgmt_req & b2x_req & b2x_read) ? `XFR_READ : (~rd_pipe_mt) ? `XFR_RDWT : (~mgmt_req & b2x_req & b2x_write) ? `XFR_WRITE : `XFR_IDLE; end // case: `XFR_RDWT `XFR_WRITE : begin rd_next = l_xfr_end & ~mgmt_req & b2x_req & b2x_read; wr_next = ~l_xfr_end | l_xfr_end & ~mgmt_req & b2x_req & b2x_write; rdok = l_xfr_end & ~mgmt_req; cb_pre_ok = 1'b0; wrok = l_xfr_end & ~mgmt_req; sel_mgmt = 1'b0; if (l_xfr_end) begin // End of transfer if (~l_wrap) begin // Current transfer was not wrap mode, may need BT // If next cmd is a R or W allow it else issue BT // This is a little pessimistic since BT is issued // for non-wrap mode transfers even if the transfer // ends on a burst boundary, but is felt to be of // minimal performance impact. sel_b2x = b2x_req & ~mgmt_req & (b2x_read | b2x_write); i_xfr_cmd = `SDR_BT; end // if (~l_wrap) else begin // Wrap mode transfer, by definition is end of burst // boundary sel_b2x = b2x_req & ~mgmt_req & ~b2x_prechg_hit; i_xfr_cmd = `SDR_DESEL; end // else: !if(~l_wrap) next_xfr_st = (~mgmt_req & b2x_req & b2x_read) ? `XFR_READ : (~mgmt_req & b2x_req & b2x_write) ? `XFR_WRITE : `XFR_IDLE; end // if (l_xfr_end) else begin // Not end of transfer // If current transfer was not wrap mode and we are at // the start of a burst boundary issue another R cmd to // step sequemtially thru memory, ELSE, // issue precharge/activate commands from the bank control if (burst_bdry & ~l_wrap) begin sel_b2x = 1'b0; i_xfr_cmd = `SDR_WRITE; end // if (burst_bdry & ~l_wrap) else begin sel_b2x = b2x_req & ~mgmt_req; i_xfr_cmd = `SDR_DESEL; end // else: !if(burst_bdry & ~l_wrap) next_xfr_st = `XFR_WRITE; end // else: !if(l_xfr_end) end // case: `XFR_WRITE endcase // case(xfr_st) end // always @ (xfr_st or ...) // signals to bank_ctl (x2b_refresh, x2b_act_ok, x2b_rdok, x2b_wrok, // x2b_pre_ok[3:0] assign x2b_refresh = (xfr_cmd == `SDR_REFRESH) ? 1'b1 : 1'b0; assign x2b_act_ok = ~act_cmd & ~d_act_cmd; assign x2b_rdok = rdok; assign x2b_wrok = wrok; assign x2b_pre_ok[0] = (l_ba == 2'b00) ? cb_pre_ok : 1'b1; assign x2b_pre_ok[1] = (l_ba == 2'b01) ? cb_pre_ok : 1'b1; assign x2b_pre_ok[2] = (l_ba == 2'b10) ? cb_pre_ok : 1'b1; assign x2b_pre_ok[3] = (l_ba == 2'b11) ? cb_pre_ok : 1'b1; assign last_burst = (ld_xfr) ? b2x_last : l_last; /************************************************************************/ // APP Data I/F wire [SDR_DW-1:0] x2a_rddt; //assign x2a_start = (ld_xfr) ? b2x_start : l_start; assign x2a_rdstart = d_rd_start; assign x2a_wrstart = wr_start; assign x2a_rdlast = d_rd_last; assign x2a_wrlast = wr_last; assign x2a_id = (ld_xfr) ? b2x_id : l_id; assign x2a_rddt = sdr_din; assign x2a_wrnext = wr_next; assign x2a_rdok = d_rd_next; /************************************************************************/ // SDRAM I/F reg sdr_cs_n, sdr_cke, sdr_ras_n, sdr_cas_n, sdr_we_n; reg [SDR_BW-1:0] sdr_dqm; reg [1:0] sdr_ba; reg [11:0] sdr_addr; reg [SDR_DW-1:0] sdr_dout; reg [SDR_BW-1:0] sdr_den_n; always @ (posedge clk) if (~reset_n) begin sdr_cs_n <= 1'b1; sdr_cke <= 1'b1; sdr_ras_n <= 1'b1; sdr_cas_n <= 1'b1; sdr_we_n <= 1'b1; sdr_dqm <= {SDR_DW{1'b1}}; sdr_den_n <= {SDR_DW{1'b1}}; end // if (~reset_n) else begin sdr_cs_n <= xfr_cmd[3]; sdr_ras_n <= xfr_cmd[2]; sdr_cas_n <= xfr_cmd[1]; sdr_we_n <= xfr_cmd[0]; sdr_cke <= (xfr_st != `XFR_IDLE) ? 1'b1 : ~(mgmt_idle & b2x_idle & r2x_idle); sdr_dqm <= (wr_next) ? app_wren_n : {SDR_BW{1'b0}}; sdr_den_n <= (wr_next) ? {SDR_BW{1'b0}} : {SDR_BW{1'b1}}; end // else: !if(~reset_n) always @ (posedge clk) begin if (~xfr_cmd[3]) begin sdr_addr <= xfr_addr; sdr_ba <= xfr_ba; end // if (~xfr_cmd[3]) sdr_dout <= (wr_next) ? app_wrdt : sdr_dout; end // always @ (posedge clk) /************************************************************************/ // Refresh and Initialization `define MGM_POWERUP 3'b000 `define MGM_PRECHARGE 3'b001 `define MGM_PCHWT 3'b010 `define MGM_REFRESH 3'b011 `define MGM_REFWT 3'b100 `define MGM_MODE_REG 3'b101 `define MGM_MODE_WT 3'b110 `define MGM_ACTIVE 3'b111 reg [2:0] mgmt_st, next_mgmt_st; reg [3:0] tmr0, tmr0_d; reg [3:0] cntr1, cntr1_d; wire tmr0_tc, cntr1_tc, rfsh_timer_tc, ref_req, precharge_ok; reg ld_tmr0, ld_cntr1, dec_cntr1, set_sdr_init_done; reg [`SDR_RFSH_TIMER_W-1 : 0] rfsh_timer; reg [`SDR_RFSH_ROW_CNT_W-1:0] rfsh_row_cnt; always @ (posedge clk) if (~reset_n) begin mgmt_st <= `MGM_POWERUP; tmr0 <= 4'b0; cntr1 <= 4'h7; rfsh_timer <= 0; rfsh_row_cnt <= 0; sdr_init_done <= 1'b0; end // if (~reset_n) else begin mgmt_st <= next_mgmt_st; tmr0 <= (ld_tmr0) ? tmr0_d : (~tmr0_tc) ? tmr0 - 1 : tmr0; cntr1 <= (ld_cntr1) ? cntr1_d : (dec_cntr1) ? cntr1 - 1 : cntr1; sdr_init_done <= (set_sdr_init_done | sdr_init_done) & sdram_enable; rfsh_timer <= (rfsh_timer_tc) ? 0 : rfsh_timer + 1; rfsh_row_cnt <= (~set_sdr_init_done) ? 0 : (rfsh_timer_tc) ? rfsh_row_cnt + 1 : rfsh_row_cnt; end // else: !if(~reset_n) assign tmr0_tc = ~|tmr0; assign cntr1_tc = ~|cntr1; assign rfsh_timer_tc = (rfsh_timer == rfsh_time) ? 1'b1 : 1'b0; assign ref_req = (rfsh_row_cnt >= rfsh_rmax) ? 1'b1 : 1'b0; assign precharge_ok = cb_pre_ok & b2x_tras_ok; assign xfr_bank_sel = l_ba; always @ (mgmt_st or sdram_enable or mgmt_ack or trp_delay or tmr0_tc or cntr1_tc or trcar_delay or rfsh_row_cnt or ref_req or sdr_init_done or precharge_ok or sdram_mode_reg) begin case (mgmt_st) // synopsys full_case parallel_case `MGM_POWERUP : begin mgmt_idle = 1'b0; mgmt_req = 1'b0; mgmt_cmd = `SDR_DESEL; mgmt_ba = 2'b0; mgmt_addr = 12'h400; // A10 = 1 => all banks ld_tmr0 = 1'b0; tmr0_d = 4'b0; dec_cntr1 = 1'b0; ld_cntr1 = 1'b1; cntr1_d = 4'hf; // changed for sdrams with higher refresh cycles during initialization set_sdr_init_done = 1'b0; next_mgmt_st = (sdram_enable) ? `MGM_PRECHARGE : `MGM_POWERUP; end // case: `MGM_POWERUP `MGM_PRECHARGE : begin // Precharge all banks mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = (precharge_ok) ? `SDR_PRECHARGE : `SDR_DESEL; mgmt_ba = 2'b0; mgmt_addr = 12'h400; // A10 = 1 => all banks ld_tmr0 = mgmt_ack; tmr0_d = trp_delay; ld_cntr1 = 1'b0; cntr1_d = 4'h7; dec_cntr1 = 1'b0; set_sdr_init_done = 1'b0; next_mgmt_st = (precharge_ok & mgmt_ack) ? `MGM_PCHWT : `MGM_PRECHARGE; end // case: `MGM_PRECHARGE `MGM_PCHWT : begin // Wait for Trp mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = `SDR_DESEL; mgmt_ba = 2'b0; mgmt_addr = 12'h400; // A10 = 1 => all banks ld_tmr0 = 1'b0; tmr0_d = trp_delay; ld_cntr1 = 1'b0; cntr1_d = 4'b0; dec_cntr1 = 1'b0; set_sdr_init_done = 1'b0; next_mgmt_st = (tmr0_tc) ? `MGM_REFRESH : `MGM_PCHWT; end // case: `MGM_PRECHARGE `MGM_REFRESH : begin // Refresh mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = `SDR_REFRESH; mgmt_ba = 2'b0; mgmt_addr = 12'h400; // A10 = 1 => all banks ld_tmr0 = mgmt_ack; tmr0_d = trcar_delay; dec_cntr1 = mgmt_ack; ld_cntr1 = 1'b0; cntr1_d = 4'h7; set_sdr_init_done = 1'b0; next_mgmt_st = (mgmt_ack) ? `MGM_REFWT : `MGM_REFRESH; end // case: `MGM_REFRESH `MGM_REFWT : begin // Wait for trcar mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = `SDR_DESEL; mgmt_ba = 2'b0; mgmt_addr = 12'h400; // A10 = 1 => all banks ld_tmr0 = 1'b0; tmr0_d = trcar_delay; dec_cntr1 = 1'b0; ld_cntr1 = 1'b0; cntr1_d = 4'h7; set_sdr_init_done = 1'b0; next_mgmt_st = (~tmr0_tc) ? `MGM_REFWT : (~cntr1_tc) ? `MGM_REFRESH : (sdr_init_done) ? `MGM_ACTIVE : `MGM_MODE_REG; end // case: `MGM_REFWT `MGM_MODE_REG : begin // Program mode Register & wait for mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = `SDR_MODE; mgmt_ba = {1'b0, sdram_mode_reg[11]}; mgmt_addr = sdram_mode_reg; ld_tmr0 = mgmt_ack; tmr0_d = 4'h7; dec_cntr1 = 1'b0; ld_cntr1 = 1'b0; cntr1_d = 4'h7; set_sdr_init_done = 1'b0; next_mgmt_st = (mgmt_ack) ? `MGM_MODE_WT : `MGM_MODE_REG; end // case: `MGM_MODE_REG `MGM_MODE_WT : begin // Wait for tMRD mgmt_idle = 1'b0; mgmt_req = 1'b1; mgmt_cmd = `SDR_DESEL; mgmt_ba = 2'bx; mgmt_addr = 12'bx; ld_tmr0 = 1'b0; tmr0_d = 4'h7; dec_cntr1 = 1'b0; ld_cntr1 = 1'b0; cntr1_d = 4'h7; set_sdr_init_done = 1'b0; next_mgmt_st = (~tmr0_tc) ? `MGM_MODE_WT : `MGM_ACTIVE; end // case: `MGM_MODE_WT `MGM_ACTIVE : begin // Wait for ref_req mgmt_idle = ~ref_req; mgmt_req = 1'b0; mgmt_cmd = `SDR_DESEL; mgmt_ba = 2'bx; mgmt_addr = 12'bx; ld_tmr0 = 1'b0; tmr0_d = 4'h7; dec_cntr1 = 1'b0; ld_cntr1 = ref_req; cntr1_d = rfsh_row_cnt; set_sdr_init_done = 1'b1; next_mgmt_st = (~sdram_enable) ? `MGM_POWERUP : (ref_req) ? `MGM_PRECHARGE : `MGM_ACTIVE; end // case: `MGM_MODE_WT endcase // case(mgmt_st) end // always @ (mgmt_st or ....) endmodule // sdr_xfr_ctl
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