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/*********************************************************************
 
  SDRAM Controller Bank Controller
 
  This file is part of the sdram controller project
  http://www.opencores.org/cores/sdr_ctrl/
 
  Description:
    This module takes requests from sdrc_req_gen, checks for page hit/miss and
    issues precharge/activate commands and then passes the request to sdrc_xfr_ctl.
 
  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_define.v"
 
module sdrc_bank_fsm (clk,
                     reset_n,
 
                     /* Req from req_gen */
                     r2b_req,      // request
                     r2b_req_id,   // ID
                     r2b_start,    // First chunk of burst
                     r2b_last,     // Last chunk of burst
                     r2b_wrap,
                     r2b_raddr,    // row address
                     r2b_caddr,    // col address
                     r2b_len,      // length
                     r2b_write,    // write request
                     b2r_ack,
                     sdr_dma_last,
 
                     /* Transfer request to xfr_ctl */
                     b2x_req,      // Request to xfr_ctl
                     b2x_start,    // first chunk of transfer
                     b2x_last,     // last chunk of transfer
                     b2x_wrap,
                     b2x_id,       // Transfer ID
                     b2x_addr,     // row/col address
                     b2x_len,      // transfer length
                     b2x_cmd,      // transfer command
                     x2b_ack,      // command accepted
 
                     /* Status to/from xfr_ctl */
                     tras_ok,      // TRAS OK for this bank
                     xfr_ok,
                     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
 
                     /* current xfr row address of the bank */
                     bank_row,
 
                     /* SDRAM Timing */
                     tras_delay,   // Active to precharge delay
                     trp_delay,    // Precharge to active delay
                     trcd_delay);  // Active to R/W delay
 
 
parameter  SDR_DW   = 16;  // SDR Data Width 
parameter  SDR_BW   = 2;   // SDR Byte Width
 
   input                        clk, reset_n;
 
   /* Req from bank_ctl */
   input                        r2b_req, r2b_start, r2b_last,
                                r2b_write, r2b_wrap;
   input [`SDR_REQ_ID_W-1:0]     r2b_req_id;
   input [12:0]          r2b_raddr;
   input [12:0]          r2b_caddr;
   input [`REQ_BW-1:0]   r2b_len;
   output                       b2r_ack;
   input                        sdr_dma_last;
 
   /* Req to xfr_ctl */
   output                       b2x_req, b2x_start, b2x_last,
                                tras_ok, b2x_wrap;
   output [`SDR_REQ_ID_W-1:0]    b2x_id;
   output [12:0]                 b2x_addr;
   output [`REQ_BW-1:0]  b2x_len;
   output [1:0]          b2x_cmd;
   input                        x2b_ack;
 
   /* Status from xfr_ctl */
   input                        x2b_refresh, x2b_act_ok, x2b_rdok,
                                x2b_wrok, x2b_pre_ok, xfr_ok;
 
   input [3:0]                   tras_delay, trp_delay, trcd_delay;
 
   output [12:0]                         bank_row;
 
   /****************************************************************************/
   // Internal Nets
 
   `define BANK_IDLE         3'b000
   `define BANK_PRE          3'b001
   `define BANK_ACT          3'b010
   `define BANK_XFR          3'b011
   `define BANK_DMA_LAST_PRE 3'b100
 
   reg [2:0]                     bank_st, next_bank_st;
   wire                         b2x_start, b2x_last;
   reg                          l_start, l_last;
   reg                          b2x_req, b2r_ack;
   wire [`SDR_REQ_ID_W-1:0]      b2x_id;
   reg [`SDR_REQ_ID_W-1:0]       l_id;
   reg [12:0]                    b2x_addr;
   reg [`REQ_BW-1:0]     l_len;
   wire [`REQ_BW-1:0]    b2x_len;
   reg [1:0]                     b2x_cmd_t;
   reg                          bank_valid;
   reg [12:0]                    bank_row;
   reg [3:0]                     tras_cntr, timer0;
   reg                          l_wrap, l_write;
   wire                         b2x_wrap;
   reg [12:0]                    l_raddr;
   reg [12:0]                    l_caddr;
   reg                          l_sdr_dma_last;
   reg                          bank_prech_page_closed;
 
   wire                         tras_ok_internal, tras_ok, activate_bank;
 
   wire                         page_hit, timer0_tc_t, ld_trp, ld_trcd;
 
   /*** Timing Break Logic Added for FPGA - Start ****/
   reg  x2b_wrok_r, xfr_ok_r , x2b_rdok_r;
   reg [1:0] b2x_cmd_r,timer0_tc_r,tras_ok_r,x2b_pre_ok_r,x2b_act_ok_r;
   always @ (posedge clk)
      if (~reset_n) begin
         x2b_wrok_r <= 1'b0;
         xfr_ok_r   <= 1'b0;
         x2b_rdok_r <= 1'b0;
         b2x_cmd_r  <= 2'b0;
         timer0_tc_r  <= 1'b0;
         tras_ok_r    <= 1'b0;
         x2b_pre_ok_r <= 1'b0;
         x2b_act_ok_r <= 1'b0;
      end
      else begin
         x2b_wrok_r <= x2b_wrok;
         xfr_ok_r   <= xfr_ok;
         x2b_rdok_r <= x2b_rdok;
         b2x_cmd_r  <= b2x_cmd_t;
         timer0_tc_r <= (ld_trp | ld_trcd) ? 1'b0 : timer0_tc_t;
         tras_ok_r   <= tras_ok_internal;
         x2b_pre_ok_r  <= x2b_pre_ok;
         x2b_act_ok_r  <= x2b_act_ok;
      end
 
 wire  x2b_wrok_t     = (`TARGET_DESIGN == `FPGA) ? x2b_wrok_r : x2b_wrok;
 wire  xfr_ok_t       = (`TARGET_DESIGN == `FPGA) ? xfr_ok_r : xfr_ok;
 wire  x2b_rdok_t     = (`TARGET_DESIGN == `FPGA) ? x2b_rdok_r : x2b_rdok;
 wire [1:0] b2x_cmd   = (`TARGET_DESIGN == `FPGA) ? b2x_cmd_r : b2x_cmd_t;
 wire  timer0_tc      = (`TARGET_DESIGN == `FPGA) ? timer0_tc_r : timer0_tc_t;
 assign  tras_ok      = (`TARGET_DESIGN == `FPGA) ? tras_ok_r : tras_ok_internal;
 wire  x2b_pre_ok_t   = (`TARGET_DESIGN == `FPGA) ? x2b_pre_ok_r : x2b_pre_ok;
 wire  x2b_act_ok_t   = (`TARGET_DESIGN == `FPGA) ? x2b_act_ok_r : x2b_act_ok;
 
   /*** Timing Break Logic Added for FPGA - End****/
 
 
   always @ (posedge clk)
      if (~reset_n) begin
         bank_valid <= 1'b0;
         tras_cntr <= 4'b0;
         timer0 <= 4'b0;
         bank_st <= `BANK_IDLE;
      end // if (~reset_n)
 
      else begin
 
         bank_valid <= (x2b_refresh || bank_prech_page_closed) ? 1'b0 :  // force the bank status to be invalid
                       (activate_bank) ? 1'b1 : bank_valid;
 
         tras_cntr <= (activate_bank) ? tras_delay :
                      (~tras_ok_internal) ? tras_cntr - 4'b1 : 4'b0;
 
         timer0 <= (ld_trp) ? trp_delay :
                   (ld_trcd) ? trcd_delay :
                   (timer0 != 'h0) ? timer0 - 4'b1 : timer0;
 
         bank_st <= next_bank_st;
 
      end // else: !if(~reset_n)
 
   always @ (posedge clk) begin
 
      bank_row <= (bank_st == `BANK_ACT) ? b2x_addr : bank_row;
 
      if (~reset_n) begin
         l_start <= 1'b0;
         l_last <= 1'b0;
         l_id <= 1'b0;
         l_len <= 1'b0;
         l_wrap <= 1'b0;
         l_write <= 1'b0;
         l_raddr <= 1'b0;
         l_caddr <= 1'b0;
         l_sdr_dma_last <= 1'b0;
      end
      else begin
        if (b2r_ack) begin
           l_start <= r2b_start;
           l_last <= r2b_last;
           l_id <= r2b_req_id;
           l_len <= r2b_len;
           l_wrap <= r2b_wrap;
           l_write <= r2b_write;
           l_raddr <= r2b_raddr;
           l_caddr <= r2b_caddr;
           l_sdr_dma_last <= sdr_dma_last;
        end // if (b2r_ack)
      end
 
   end // always @ (posedge clk)
 
   assign tras_ok_internal = ~|tras_cntr;
 
   assign activate_bank = (b2x_cmd == `OP_ACT) & x2b_ack;
 
   assign page_hit = (r2b_raddr == bank_row) ? bank_valid : 1'b0;    // its a hit only if bank is valid
 
   assign timer0_tc_t = ~|timer0;
 
   assign ld_trp = (b2x_cmd == `OP_PRE) ? x2b_ack : 1'b0;
 
   assign ld_trcd = (b2x_cmd == `OP_ACT) ? x2b_ack : 1'b0;
 
 
 
   always @ (*) begin
 
       bank_prech_page_closed = 1'b0;
       b2x_req = 1'b0;
       b2x_cmd_t = 2'bx;
       b2r_ack = 1'b0;
       b2x_addr = 13'bx;
       next_bank_st = bank_st;
 
      case (bank_st)
 
        `BANK_IDLE : begin
                if(`TARGET_DESIGN == `FPGA) begin // To break the timing, b2x request are generated delayed
                     if (~r2b_req) begin
                        next_bank_st = `BANK_IDLE;
                     end // if (~r2b_req)
                     else if (page_hit) begin
                        b2r_ack = 1'b1;
                        b2x_cmd_t = (r2b_write) ? `OP_WR : `OP_RD;
                        next_bank_st = `BANK_XFR;
                     end // if (page_hit)
                     else begin  // page_miss
                        b2r_ack = 1'b1;
                        b2x_cmd_t = `OP_PRE;
                        next_bank_st = `BANK_PRE;  // bank was precharged on l_sdr_dma_last
                     end // else: !if(page_hit)
                end else begin // ASIC
                     if (~r2b_req) begin
                        bank_prech_page_closed = 1'b0;
                        b2x_req = 1'b0;
                        b2x_cmd_t = 2'bx;
                        b2r_ack = 1'b0;
                        b2x_addr = 13'bx;
                        next_bank_st = `BANK_IDLE;
                     end // if (~r2b_req)
                     else if (page_hit) begin
                        b2x_req = (r2b_write) ? x2b_wrok_t & xfr_ok_t :
                                               x2b_rdok_t & xfr_ok_t;
                        b2x_cmd_t = (r2b_write) ? `OP_WR : `OP_RD;
                        b2r_ack = 1'b1;
                        b2x_addr = r2b_caddr;
                        next_bank_st = (x2b_ack) ? `BANK_IDLE : `BANK_XFR;  // in case of hit, stay here till xfr sm acks
                     end // if (page_hit)
                     else begin  // page_miss
                        b2x_req = tras_ok & x2b_pre_ok_t;
                        b2x_cmd_t = `OP_PRE;
                        b2r_ack = 1'b1;
                        b2x_addr = r2b_raddr & 13'hBFF;    // Dont want to pre all banks!
                        next_bank_st = (l_sdr_dma_last) ? `BANK_PRE : (x2b_ack) ? `BANK_ACT : `BANK_PRE;  // bank was precharged on l_sdr_dma_last
                     end // else: !if(page_hit)
                end
        end // case: `BANK_IDLE
 
        `BANK_PRE : begin
           b2x_req = tras_ok & x2b_pre_ok_t;
           b2x_cmd_t = `OP_PRE;
           b2r_ack = 1'b0;
           b2x_addr = l_raddr & 13'hBFF;           // Dont want to pre all banks!
           bank_prech_page_closed = 1'b0;
           next_bank_st = (x2b_ack) ? `BANK_ACT : `BANK_PRE;
        end // case: `BANK_PRE
 
        `BANK_ACT : begin
           b2x_req = timer0_tc & x2b_act_ok_t;
           b2x_cmd_t = `OP_ACT;
           b2r_ack = 1'b0;
           b2x_addr = l_raddr;
           bank_prech_page_closed = 1'b0;
           next_bank_st = (x2b_ack) ? `BANK_XFR : `BANK_ACT;
        end // case: `BANK_ACT
 
        `BANK_XFR : begin
           b2x_req = (l_write) ? timer0_tc & x2b_wrok_t & xfr_ok_t :
                     timer0_tc & x2b_rdok_t & xfr_ok_t;
           b2x_cmd_t = (l_write) ? `OP_WR : `OP_RD;
           b2r_ack = 1'b0;
           b2x_addr = l_caddr;
           bank_prech_page_closed = 1'b0;
           next_bank_st = (x2b_refresh) ? `BANK_ACT :
                          (x2b_ack & l_sdr_dma_last) ? `BANK_DMA_LAST_PRE :
                          (x2b_ack) ? `BANK_IDLE : `BANK_XFR;
        end // case: `BANK_XFR
 
        `BANK_DMA_LAST_PRE : begin
           b2x_req = tras_ok & x2b_pre_ok_t;
           b2x_cmd_t = `OP_PRE;
           b2r_ack = 1'b0;
           b2x_addr = l_raddr & 13'hBFF;           // Dont want to pre all banks!
           bank_prech_page_closed = 1'b1;
           next_bank_st = (x2b_ack) ? `BANK_IDLE : `BANK_DMA_LAST_PRE;
        end // case: `BANK_DMA_LAST_PRE
 
      endcase // case(bank_st)
 
   end // always @ (bank_st or ...)
 
   assign b2x_start = (bank_st == `BANK_IDLE) ? r2b_start : l_start;
 
   assign b2x_last = (bank_st == `BANK_IDLE) ? r2b_last : l_last;
 
   assign b2x_id = (bank_st == `BANK_IDLE) ? r2b_req_id : l_id;
 
   assign b2x_len = (bank_st == `BANK_IDLE) ? r2b_len : l_len;
 
   assign b2x_wrap = (bank_st == `BANK_IDLE) ? r2b_wrap : l_wrap;
 
endmodule // sdr_bank_fsm

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[/] [yifive/] [trunk/] [caravel_yifive/] [verilog/] [rtl/] [sdram_ctrl/] [src/] [core/] [sdrc_bank_fsm.v] - Blame information for rev 19

Line No.	Rev	Author	Line
1	19	dinesha	`/*********************************************************************`
2
3			`SDRAM Controller Bank Controller`
4
5			`This file is part of the sdram controller project`
6			`http://www.opencores.org/cores/sdr_ctrl/`
7
8			`Description:`
9			`This module takes requests from sdrc_req_gen, checks for page hit/miss and`
10			`issues precharge/activate commands and then passes the request to sdrc_xfr_ctl.`
11
12			`To Do:`
13			`nothing`
14
15			`Author(s):`
16			`- Dinesh Annayya, dinesha@opencores.org`
17			`Version : 1.0 - 8th Jan 2012`
18
19
20
21			`Copyright (C) 2000 Authors and OPENCORES.ORG`
22
23			`This source file may be used and distributed without`
24			`restriction provided that this copyright statement is not`
25			`removed from the file and that any derivative work contains`
26			`the original copyright notice and the associated disclaimer.`
27
28			`This source file is free software; you can redistribute it`
29			`and/or modify it under the terms of the GNU Lesser General`
30			`Public License as published by the Free Software Foundation;`
31			`either version 2.1 of the License, or (at your option) any`
32			`later version.`
33
34			`This source is distributed in the hope that it will be`
35			`useful, but WITHOUT ANY WARRANTY; without even the implied`
36			`warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR`
37			`PURPOSE. See the GNU Lesser General Public License for more`
38			`details.`
39
40			`You should have received a copy of the GNU Lesser General`
41			`Public License along with this source; if not, download it`
42			`from http://www.opencores.org/lgpl.shtml`
43
44			`*******************************************************************/`
45
46
47			`include "sdrc_define.v"
48
49			`module sdrc_bank_fsm (clk,`
50			`reset_n,`
51
52			`/* Req from req_gen */`
53			`r2b_req, // request`
54			`r2b_req_id, // ID`
55			`r2b_start, // First chunk of burst`
56			`r2b_last, // Last chunk of burst`
57			`r2b_wrap,`
58			`r2b_raddr, // row address`
59			`r2b_caddr, // col address`
60			`r2b_len, // length`
61			`r2b_write, // write request`
62			`b2r_ack,`
63			`sdr_dma_last,`
64
65			`/* Transfer request to xfr_ctl */`
66			`b2x_req, // Request to xfr_ctl`
67			`b2x_start, // first chunk of transfer`
68			`b2x_last, // last chunk of transfer`
69			`b2x_wrap,`
70			`b2x_id, // Transfer ID`
71			`b2x_addr, // row/col address`
72			`b2x_len, // transfer length`
73			`b2x_cmd, // transfer command`
74			`x2b_ack, // command accepted`
75
76			`/* Status to/from xfr_ctl */`
77			`tras_ok, // TRAS OK for this bank`
78			`xfr_ok,`
79			`x2b_refresh, // We did a refresh`
80			`x2b_pre_ok, // OK to do a precharge (per bank)`
81			`x2b_act_ok, // OK to do an activate`
82			`x2b_rdok, // OK to do a read`
83			`x2b_wrok, // OK to do a write`
84
85			`/* current xfr row address of the bank */`
86			`bank_row,`
87
88			`/* SDRAM Timing */`
89			`tras_delay, // Active to precharge delay`
90			`trp_delay, // Precharge to active delay`
91			`trcd_delay); // Active to R/W delay`
92
93
94			`parameter SDR_DW = 16; // SDR Data Width`
95			`parameter SDR_BW = 2; // SDR Byte Width`
96
97			`input clk, reset_n;`
98
99			`/* Req from bank_ctl */`
100			`input r2b_req, r2b_start, r2b_last,`
101			`r2b_write, r2b_wrap;`
102			input [`SDR_REQ_ID_W-1:0] r2b_req_id;
103			`input [12:0] r2b_raddr;`
104			`input [12:0] r2b_caddr;`
105			input [`REQ_BW-1:0] r2b_len;
106			`output b2r_ack;`
107			`input sdr_dma_last;`
108
109			`/* Req to xfr_ctl */`
110			`output b2x_req, b2x_start, b2x_last,`
111			`tras_ok, b2x_wrap;`
112			output [`SDR_REQ_ID_W-1:0] b2x_id;
113			`output [12:0] b2x_addr;`
114			output [`REQ_BW-1:0] b2x_len;
115			`output [1:0] b2x_cmd;`
116			`input x2b_ack;`
117
118			`/* Status from xfr_ctl */`
119			`input x2b_refresh, x2b_act_ok, x2b_rdok,`
120			`x2b_wrok, x2b_pre_ok, xfr_ok;`
121
122			`input [3:0] tras_delay, trp_delay, trcd_delay;`
123
124			`output [12:0] bank_row;`
125
126			`/****************************************************************************/`
127			`// Internal Nets`
128
129			`define BANK_IDLE 3'b000
130			`define BANK_PRE 3'b001
131			`define BANK_ACT 3'b010
132			`define BANK_XFR 3'b011
133			`define BANK_DMA_LAST_PRE 3'b100
134
135			`reg [2:0] bank_st, next_bank_st;`
136			`wire b2x_start, b2x_last;`
137			`reg l_start, l_last;`
138			`reg b2x_req, b2r_ack;`
139			wire [`SDR_REQ_ID_W-1:0] b2x_id;
140			reg [`SDR_REQ_ID_W-1:0] l_id;
141			`reg [12:0] b2x_addr;`
142			reg [`REQ_BW-1:0] l_len;
143			wire [`REQ_BW-1:0] b2x_len;
144			`reg [1:0] b2x_cmd_t;`
145			`reg bank_valid;`
146			`reg [12:0] bank_row;`
147			`reg [3:0] tras_cntr, timer0;`
148			`reg l_wrap, l_write;`
149			`wire b2x_wrap;`
150			`reg [12:0] l_raddr;`
151			`reg [12:0] l_caddr;`
152			`reg l_sdr_dma_last;`
153			`reg bank_prech_page_closed;`
154
155			`wire tras_ok_internal, tras_ok, activate_bank;`
156
157			`wire page_hit, timer0_tc_t, ld_trp, ld_trcd;`
158
159			`/* Timing Break Logic Added for FPGA - Start **/`
160			`reg x2b_wrok_r, xfr_ok_r , x2b_rdok_r;`
161			`reg [1:0] b2x_cmd_r,timer0_tc_r,tras_ok_r,x2b_pre_ok_r,x2b_act_ok_r;`
162			`always @ (posedge clk)`
163			`if (~reset_n) begin`
164			`x2b_wrok_r <= 1'b0;`
165			`xfr_ok_r <= 1'b0;`
166			`x2b_rdok_r <= 1'b0;`
167			`b2x_cmd_r <= 2'b0;`
168			`timer0_tc_r <= 1'b0;`
169			`tras_ok_r <= 1'b0;`
170			`x2b_pre_ok_r <= 1'b0;`
171			`x2b_act_ok_r <= 1'b0;`
172			`end`
173			`else begin`
174			`x2b_wrok_r <= x2b_wrok;`
175			`xfr_ok_r <= xfr_ok;`
176			`x2b_rdok_r <= x2b_rdok;`
177			`b2x_cmd_r <= b2x_cmd_t;`
178			`timer0_tc_r <= (ld_trp \| ld_trcd) ? 1'b0 : timer0_tc_t;`
179			`tras_ok_r <= tras_ok_internal;`
180			`x2b_pre_ok_r <= x2b_pre_ok;`
181			`x2b_act_ok_r <= x2b_act_ok;`
182			`end`
183
184			wire x2b_wrok_t = (`TARGET_DESIGN == `FPGA) ? x2b_wrok_r : x2b_wrok;
185			wire xfr_ok_t = (`TARGET_DESIGN == `FPGA) ? xfr_ok_r : xfr_ok;
186			wire x2b_rdok_t = (`TARGET_DESIGN == `FPGA) ? x2b_rdok_r : x2b_rdok;
187			wire [1:0] b2x_cmd = (`TARGET_DESIGN == `FPGA) ? b2x_cmd_r : b2x_cmd_t;
188			wire timer0_tc = (`TARGET_DESIGN == `FPGA) ? timer0_tc_r : timer0_tc_t;
189			assign tras_ok = (`TARGET_DESIGN == `FPGA) ? tras_ok_r : tras_ok_internal;
190			wire x2b_pre_ok_t = (`TARGET_DESIGN == `FPGA) ? x2b_pre_ok_r : x2b_pre_ok;
191			wire x2b_act_ok_t = (`TARGET_DESIGN == `FPGA) ? x2b_act_ok_r : x2b_act_ok;
192
193			`/* Timing Break Logic Added for FPGA - End**/`
194
195
196			`always @ (posedge clk)`
197			`if (~reset_n) begin`
198			`bank_valid <= 1'b0;`
199			`tras_cntr <= 4'b0;`
200			`timer0 <= 4'b0;`
201			bank_st <= `BANK_IDLE;
202			`end // if (~reset_n)`
203
204			`else begin`
205
206			`bank_valid <= (x2b_refresh \|\| bank_prech_page_closed) ? 1'b0 : // force the bank status to be invalid`
207			`(activate_bank) ? 1'b1 : bank_valid;`
208
209			`tras_cntr <= (activate_bank) ? tras_delay :`
210			`(~tras_ok_internal) ? tras_cntr - 4'b1 : 4'b0;`
211
212			`timer0 <= (ld_trp) ? trp_delay :`
213			`(ld_trcd) ? trcd_delay :`
214			`(timer0 != 'h0) ? timer0 - 4'b1 : timer0;`
215
216			`bank_st <= next_bank_st;`
217
218			`end // else: !if(~reset_n)`
219
220			`always @ (posedge clk) begin`
221
222			bank_row <= (bank_st == `BANK_ACT) ? b2x_addr : bank_row;
223
224			`if (~reset_n) begin`
225			`l_start <= 1'b0;`
226			`l_last <= 1'b0;`
227			`l_id <= 1'b0;`
228			`l_len <= 1'b0;`
229			`l_wrap <= 1'b0;`
230			`l_write <= 1'b0;`
231			`l_raddr <= 1'b0;`
232			`l_caddr <= 1'b0;`
233			`l_sdr_dma_last <= 1'b0;`
234			`end`
235			`else begin`
236			`if (b2r_ack) begin`
237			`l_start <= r2b_start;`
238			`l_last <= r2b_last;`
239			`l_id <= r2b_req_id;`
240			`l_len <= r2b_len;`
241			`l_wrap <= r2b_wrap;`
242			`l_write <= r2b_write;`
243			`l_raddr <= r2b_raddr;`
244			`l_caddr <= r2b_caddr;`
245			`l_sdr_dma_last <= sdr_dma_last;`
246			`end // if (b2r_ack)`
247			`end`
248
249			`end // always @ (posedge clk)`
250
251			`assign tras_ok_internal = ~\|tras_cntr;`
252
253			assign activate_bank = (b2x_cmd == `OP_ACT) & x2b_ack;
254
255			`assign page_hit = (r2b_raddr == bank_row) ? bank_valid : 1'b0; // its a hit only if bank is valid`
256
257			`assign timer0_tc_t = ~\|timer0;`
258
259			assign ld_trp = (b2x_cmd == `OP_PRE) ? x2b_ack : 1'b0;
260
261			assign ld_trcd = (b2x_cmd == `OP_ACT) ? x2b_ack : 1'b0;
262
263
264
265			`always @ (*) begin`
266
267			`bank_prech_page_closed = 1'b0;`
268			`b2x_req = 1'b0;`
269			`b2x_cmd_t = 2'bx;`
270			`b2r_ack = 1'b0;`
271			`b2x_addr = 13'bx;`
272			`next_bank_st = bank_st;`
273
274			`case (bank_st)`
275
276			`BANK_IDLE : begin
277			if(`TARGET_DESIGN == `FPGA) begin // To break the timing, b2x request are generated delayed
278			`if (~r2b_req) begin`
279			next_bank_st = `BANK_IDLE;
280			`end // if (~r2b_req)`
281			`else if (page_hit) begin`
282			`b2r_ack = 1'b1;`
283			b2x_cmd_t = (r2b_write) ? `OP_WR : `OP_RD;
284			next_bank_st = `BANK_XFR;
285			`end // if (page_hit)`
286			`else begin // page_miss`
287			`b2r_ack = 1'b1;`
288			b2x_cmd_t = `OP_PRE;
289			next_bank_st = `BANK_PRE; // bank was precharged on l_sdr_dma_last
290			`end // else: !if(page_hit)`
291			`end else begin // ASIC`
292			`if (~r2b_req) begin`
293			`bank_prech_page_closed = 1'b0;`
294			`b2x_req = 1'b0;`
295			`b2x_cmd_t = 2'bx;`
296			`b2r_ack = 1'b0;`
297			`b2x_addr = 13'bx;`
298			next_bank_st = `BANK_IDLE;
299			`end // if (~r2b_req)`
300			`else if (page_hit) begin`
301			`b2x_req = (r2b_write) ? x2b_wrok_t & xfr_ok_t :`
302			`x2b_rdok_t & xfr_ok_t;`
303			b2x_cmd_t = (r2b_write) ? `OP_WR : `OP_RD;
304			`b2r_ack = 1'b1;`
305			`b2x_addr = r2b_caddr;`
306			next_bank_st = (x2b_ack) ? `BANK_IDLE : `BANK_XFR; // in case of hit, stay here till xfr sm acks
307			`end // if (page_hit)`
308			`else begin // page_miss`
309			`b2x_req = tras_ok & x2b_pre_ok_t;`
310			b2x_cmd_t = `OP_PRE;
311			`b2r_ack = 1'b1;`
312			`b2x_addr = r2b_raddr & 13'hBFF; // Dont want to pre all banks!`
313			next_bank_st = (l_sdr_dma_last) ? `BANK_PRE : (x2b_ack) ? `BANK_ACT : `BANK_PRE; // bank was precharged on l_sdr_dma_last
314			`end // else: !if(page_hit)`
315			`end`
316			end // case: `BANK_IDLE
317
318			`BANK_PRE : begin
319			`b2x_req = tras_ok & x2b_pre_ok_t;`
320			b2x_cmd_t = `OP_PRE;
321			`b2r_ack = 1'b0;`
322			`b2x_addr = l_raddr & 13'hBFF; // Dont want to pre all banks!`
323			`bank_prech_page_closed = 1'b0;`
324			next_bank_st = (x2b_ack) ? `BANK_ACT : `BANK_PRE;
325			end // case: `BANK_PRE
326
327			`BANK_ACT : begin
328			`b2x_req = timer0_tc & x2b_act_ok_t;`
329			b2x_cmd_t = `OP_ACT;
330			`b2r_ack = 1'b0;`
331			`b2x_addr = l_raddr;`
332			`bank_prech_page_closed = 1'b0;`
333			next_bank_st = (x2b_ack) ? `BANK_XFR : `BANK_ACT;
334			end // case: `BANK_ACT
335
336			`BANK_XFR : begin
337			`b2x_req = (l_write) ? timer0_tc & x2b_wrok_t & xfr_ok_t :`
338			`timer0_tc & x2b_rdok_t & xfr_ok_t;`
339			b2x_cmd_t = (l_write) ? `OP_WR : `OP_RD;
340			`b2r_ack = 1'b0;`
341			`b2x_addr = l_caddr;`
342			`bank_prech_page_closed = 1'b0;`
343			next_bank_st = (x2b_refresh) ? `BANK_ACT :
344			(x2b_ack & l_sdr_dma_last) ? `BANK_DMA_LAST_PRE :
345			(x2b_ack) ? `BANK_IDLE : `BANK_XFR;
346			end // case: `BANK_XFR
347
348			`BANK_DMA_LAST_PRE : begin
349			`b2x_req = tras_ok & x2b_pre_ok_t;`
350			b2x_cmd_t = `OP_PRE;
351			`b2r_ack = 1'b0;`
352			`b2x_addr = l_raddr & 13'hBFF; // Dont want to pre all banks!`
353			`bank_prech_page_closed = 1'b1;`
354			next_bank_st = (x2b_ack) ? `BANK_IDLE : `BANK_DMA_LAST_PRE;
355			end // case: `BANK_DMA_LAST_PRE
356
357			`endcase // case(bank_st)`
358
359			`end // always @ (bank_st or ...)`
360
361			assign b2x_start = (bank_st == `BANK_IDLE) ? r2b_start : l_start;
362
363			assign b2x_last = (bank_st == `BANK_IDLE) ? r2b_last : l_last;
364
365			assign b2x_id = (bank_st == `BANK_IDLE) ? r2b_req_id : l_id;
366
367			assign b2x_len = (bank_st == `BANK_IDLE) ? r2b_len : l_len;
368
369			assign b2x_wrap = (bank_st == `BANK_IDLE) ? r2b_wrap : l_wrap;
370
371			`endmodule // sdr_bank_fsm`