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[/] [spimaster/] [trunk/] [RTL/] [readWriteSDBlock.v] - Blame information for rev 2

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1 2 sfielding
 
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//////////////////////////////////////////////////////////////////////
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////                                                              ////
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//// readWriteSDBlock.v                             ////
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////                                                              ////
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//// This file is part of the spiMaster opencores effort.
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//// <http://www.opencores.org/cores//>                           ////
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////                                                              ////
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//// Module Description:                                          ////
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//// If readWriteSDBlockReq equals WRITE_SD_BLOCK or
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//// READ_SD_BLOCK, then write or read a 512 byte block
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//// of SD memory
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//// 
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////                                                              ////
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//// To Do:                                                       ////
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//// 
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////                                                              ////
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//// Author(s):                                                   ////
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//// - Steve Fielding, sfielding@base2designs.com                 ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
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////                                                              ////
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//// Copyright (C) 2004 Steve Fielding and OPENCORES.ORG          ////
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////                                                              ////
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//// This source file may be used and distributed without         ////
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//// restriction provided that this copyright statement is not    ////
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//// removed from the file and that any derivative work contains  ////
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//// the original copyright notice and the associated disclaimer. ////
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////                                                              ////
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//// This source file is free software; you can redistribute it   ////
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//// and/or modify it under the terms of the GNU Lesser General   ////
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//// Public License as published by the Free Software Foundation; ////
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//// either version 2.1 of the License, or (at your option) any   ////
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//// later version.                                               ////
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////                                                              ////
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//// This source is distributed in the hope that it will be       ////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
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//// PURPOSE. See the GNU Lesser General Public License for more  ////
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//// details.                                                     ////
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////                                                              ////
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//// You should have received a copy of the GNU Lesser General    ////
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//// Public License along with this source; if not, download it   ////
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//// from <http://www.opencores.org/lgpl.shtml>                   ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
47
//
48
`include "timescale.v"
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`include "spiMaster_defines.v"
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51
module readWriteSDBlock (blockAddr, checkSumByte, clk, cmdByte, dataByte1, dataByte2, dataByte3, dataByte4, readError, readWriteSDBlockRdy, readWriteSDBlockReq, respByte, respTout, rst, rxDataIn, rxDataRdy, rxDataRdyClr, rxFifoData, rxFifoWen, sendCmdRdy, sendCmdReq, spiCS_n, txDataEmpty, txDataFull, txDataOut, txDataWen, txFifoData, txFifoRen, writeError);
52
input   [31:0]blockAddr;
53
input   clk;
54
input   [1:0]readWriteSDBlockReq;
55
input   [7:0]respByte;
56
input   respTout;
57
input   rst;
58
input   [7:0]rxDataIn;
59
input   rxDataRdy;
60
input   sendCmdRdy;
61
input   txDataEmpty;
62
input   txDataFull;
63
input   [7:0]txFifoData;
64
output  [7:0]checkSumByte;
65
output  [7:0]cmdByte;
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output  [7:0]dataByte1;
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output  [7:0]dataByte2;
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output  [7:0]dataByte3;
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output  [7:0]dataByte4;
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output  [1:0]readError;
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output  readWriteSDBlockRdy;
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output  rxDataRdyClr;
73
output  [7:0]rxFifoData;
74
output  rxFifoWen;
75
output  sendCmdReq;
76
output  spiCS_n;
77
output  [7:0]txDataOut;
78
output  txDataWen;
79
output  txFifoRen;
80
output  [1:0]writeError;
81
 
82
wire    [31:0]blockAddr;
83
reg     [7:0]checkSumByte, next_checkSumByte;
84
wire    clk;
85
reg     [7:0]cmdByte, next_cmdByte;
86
reg     [7:0]dataByte1, next_dataByte1;
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reg     [7:0]dataByte2, next_dataByte2;
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reg     [7:0]dataByte3, next_dataByte3;
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reg     [7:0]dataByte4, next_dataByte4;
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reg     [1:0]readError, next_readError;
91
reg     readWriteSDBlockRdy, next_readWriteSDBlockRdy;
92
wire    [1:0]readWriteSDBlockReq;
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wire    [7:0]respByte;
94
wire    respTout;
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wire    rst;
96
wire    [7:0]rxDataIn;
97
wire    rxDataRdy;
98
reg     rxDataRdyClr, next_rxDataRdyClr;
99
reg     [7:0]rxFifoData, next_rxFifoData;
100
reg     rxFifoWen, next_rxFifoWen;
101
wire    sendCmdRdy;
102
reg     sendCmdReq, next_sendCmdReq;
103
reg     spiCS_n, next_spiCS_n;
104
wire    txDataEmpty;
105
wire    txDataFull;
106
reg     [7:0]txDataOut, next_txDataOut;
107
reg     txDataWen, next_txDataWen;
108
wire    [7:0]txFifoData;
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reg     txFifoRen, next_txFifoRen;
110
reg     [1:0]writeError, next_writeError;
111
 
112
// diagram signals declarations
113
reg  [7:0]delCnt1, next_delCnt1;
114
reg  [7:0]delCnt2, next_delCnt2;
115
reg  [7:0]locRespByte, next_locRespByte;
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reg  [8:0]loopCnt, next_loopCnt;
117
reg  [11:0]timeOutCnt, next_timeOutCnt;
118
 
119
// BINARY ENCODED state machine: rwBlkSt
120
// State codes definitions:
121
`define ST_RW_SD 6'b000000
122
`define WR_CMD_SEND_CMD 6'b000001
123
`define WR_CMD_WT_FIN 6'b000010
124
`define WR_CMD_DEL 6'b000011
125
`define WT_REQ 6'b000100
126
`define WR_TOKEN_FF1_FIN 6'b000101
127
`define WR_TOKEN_FF1_ST 6'b000110
128
`define WR_TOKEN_FF2_FIN 6'b000111
129
`define WR_TOKEN_FF2_ST 6'b001000
130
`define WR_TOKEN_FE_FIN 6'b001001
131
`define WR_TOKEN_FE_ST 6'b001010
132
`define WR_DATA_D_FIN 6'b001011
133
`define WR_DATA_D_ST 6'b001100
134
`define WR_DATA_RD_FIFO1 6'b001101
135
`define WR_DATA_RD_FIFO2 6'b001110
136
`define WR_DATA_LOOP_INIT 6'b001111
137
`define WR_DATA_CS_ST1 6'b010000
138
`define WR_DATA_CS_FIN1 6'b010001
139
`define WR_DATA_CS_FIN2 6'b010010
140
`define WR_DATA_CS_ST2 6'b010011
141
`define WR_DATA_CHK_RESP 6'b010100
142
`define WR_DATA_REQ_RESP_ST 6'b010101
143
`define WR_DATA_REQ_RESP_FIN 6'b010110
144
`define RD_CMD_SEND_CMD 6'b010111
145
`define RD_CMD_WT_FIN 6'b011000
146
`define RD_CMD_DEL 6'b011001
147
`define RD_TOKEN_CHK_LOOP 6'b011010
148
`define RD_TOKEN_WT_FIN 6'b011011
149
`define RD_TOKEN_SEND_CMD 6'b011100
150
`define RD_TOKEN_DEL2 6'b011101
151
`define RD_TOKEN_INIT_LOOP 6'b011110
152
`define RD_TOKEN_DEL1 6'b011111
153
`define RD_DATA_ST_LOOP 6'b100000
154
`define RD_DATA_WT_DATA 6'b100001
155
`define RD_DATA_CHK_LOOP 6'b100010
156
`define RD_DATA_CLR_RX 6'b100011
157
`define RD_DATA_CS_FIN2 6'b100100
158
`define RD_DATA_CS_FIN1 6'b100101
159
`define RD_DATA_CS_ST1 6'b100110
160
`define RD_DATA_CS_ST2 6'b100111
161
`define WR_BUSY_CHK_FIN 6'b101000
162
`define WR_BUSY_WT_FIN1 6'b101001
163
`define WR_BUSY_DEL1 6'b101010
164
`define WR_BUSY_SEND_CMD1 6'b101011
165
`define WR_BUSY_DEL2 6'b101100
166
`define WR_BUSY_INIT_LOOP 6'b101101
167
`define RD_TOKEN_DEL3 6'b101110
168
`define WR_DATA_DEL 6'b101111
169
 
170
reg [5:0]CurrState_rwBlkSt, NextState_rwBlkSt;
171
 
172
// Diagram actions (continuous assignments allowed only: assign ...)
173
// diagram ACTION
174
 
175
 
176
// Machine: rwBlkSt
177
 
178
// NextState logic (combinatorial)
179
always @ (blockAddr or sendCmdRdy or respTout or respByte or readWriteSDBlockReq or txDataFull or loopCnt or txFifoData or txDataEmpty or timeOutCnt or locRespByte or rxDataRdy or rxDataIn or delCnt1 or delCnt2 or readWriteSDBlockRdy or spiCS_n or readError or writeError or txDataOut or txDataWen or rxDataRdyClr or cmdByte or dataByte1 or dataByte2 or dataByte3 or dataByte4 or checkSumByte or sendCmdReq or txFifoRen or rxFifoWen or rxFifoData or CurrState_rwBlkSt)
180
begin
181
  NextState_rwBlkSt <= CurrState_rwBlkSt;
182
  // Set default values for outputs and signals
183
  next_readWriteSDBlockRdy <= readWriteSDBlockRdy;
184
  next_spiCS_n <= spiCS_n;
185
  next_readError <= readError;
186
  next_writeError <= writeError;
187
  next_txDataOut <= txDataOut;
188
  next_txDataWen <= txDataWen;
189
  next_rxDataRdyClr <= rxDataRdyClr;
190
  next_cmdByte <= cmdByte;
191
  next_dataByte1 <= dataByte1;
192
  next_dataByte2 <= dataByte2;
193
  next_dataByte3 <= dataByte3;
194
  next_dataByte4 <= dataByte4;
195
  next_checkSumByte <= checkSumByte;
196
  next_sendCmdReq <= sendCmdReq;
197
  next_loopCnt <= loopCnt;
198
  next_delCnt1 <= delCnt1;
199
  next_delCnt2 <= delCnt2;
200
  next_txFifoRen <= txFifoRen;
201
  next_rxFifoWen <= rxFifoWen;
202
  next_rxFifoData <= rxFifoData;
203
  next_timeOutCnt <= timeOutCnt;
204
  next_locRespByte <= locRespByte;
205
  case (CurrState_rwBlkSt)  // synopsys parallel_case full_case
206
    `ST_RW_SD:
207
    begin
208
      next_readWriteSDBlockRdy <= 1'b0;
209
      next_spiCS_n <= 1'b1;
210
      next_readError <= 1'b0;
211
      next_writeError <= 1'b0;
212
      next_txDataOut <= 8'h00;
213
      next_txDataWen <= 1'b0;
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      next_rxDataRdyClr <= 1'b0;
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      next_cmdByte <= 8'h00;
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      next_dataByte1 <= 8'h00;
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      next_dataByte2 <= 8'h00;
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      next_dataByte3 <= 8'h00;
219
      next_dataByte4 <= 8'h00;
220
      next_checkSumByte <= 8'h00;
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      next_sendCmdReq <= 1'b0;
222
      next_loopCnt <= 8'h00;
223
      next_delCnt1 <= 8'h00;
224
      next_delCnt2 <= 8'h00;
225
      next_readError <= `READ_NO_ERROR;
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      next_writeError <= `WRITE_NO_ERROR;
227
      next_txFifoRen <= 1'b0;
228
      next_rxFifoWen <= 1'b0;
229
      next_rxFifoData <= 8'h00;
230
      next_timeOutCnt <= 12'h000;
231
      next_locRespByte <= 8'h00;
232
      NextState_rwBlkSt <= `WT_REQ;
233
    end
234
    `WT_REQ:
235
    begin
236
      next_spiCS_n <= 1'b1;
237
      next_readWriteSDBlockRdy <= 1'b1;
238
      next_cmdByte <= 8'h00;
239
      next_dataByte1 <= 8'h00;
240
      next_dataByte2 <= 8'h00;
241
      next_dataByte3 <= 8'h00;
242
      next_dataByte4 <= 8'h00;
243
      next_checkSumByte <= 8'h00;
244
      if (readWriteSDBlockReq == `READ_SD_BLOCK)
245
      begin
246
        NextState_rwBlkSt <= `RD_CMD_SEND_CMD;
247
        next_spiCS_n <= 1'b0;
248
        next_readWriteSDBlockRdy <= 1'b0;
249
        next_readError <= `READ_NO_ERROR;
250
      end
251
      else if (readWriteSDBlockReq == `WRITE_SD_BLOCK)
252
      begin
253
        NextState_rwBlkSt <= `WR_CMD_SEND_CMD;
254
        next_spiCS_n <= 1'b0;
255
        next_readWriteSDBlockRdy <= 1'b0;
256
        next_writeError <= `WRITE_NO_ERROR;
257
      end
258
    end
259
    `WR_CMD_SEND_CMD:
260
    begin
261
      next_cmdByte <= 8'h58;
262
      //CMD24 Block Write
263
      next_dataByte1 <= blockAddr[31:24];
264
      next_dataByte2 <= blockAddr[23:16];
265
      next_dataByte3 <= blockAddr[15:8];
266
      next_dataByte4 <= blockAddr[7:0];
267
      next_checkSumByte <= 8'hff;
268
      next_sendCmdReq <= 1'b1;
269
      NextState_rwBlkSt <= `WR_CMD_DEL;
270
    end
271
    `WR_CMD_WT_FIN:
272
    begin
273
      if ((sendCmdRdy == 1'b1) && (respTout == 1'b1 || respByte != 8'h00))
274
      begin
275
        NextState_rwBlkSt <= `WT_REQ;
276
        next_writeError <= `WRITE_CMD_ERROR;
277
      end
278
      else if (sendCmdRdy == 1'b1)
279
      begin
280
        NextState_rwBlkSt <= `WR_TOKEN_FF1_ST;
281
      end
282
    end
283
    `WR_CMD_DEL:
284
    begin
285
      next_sendCmdReq <= 1'b0;
286
      NextState_rwBlkSt <= `WR_CMD_WT_FIN;
287
    end
288
    `WR_TOKEN_FF1_FIN:
289
    begin
290
      next_txDataWen <= 1'b0;
291
      NextState_rwBlkSt <= `WR_TOKEN_FF2_ST;
292
    end
293
    `WR_TOKEN_FF1_ST:
294
    begin
295
      if (txDataFull == 1'b0)
296
      begin
297
        NextState_rwBlkSt <= `WR_TOKEN_FF1_FIN;
298
        next_txDataOut <= 8'hff;
299
        next_txDataWen <= 1'b1;
300
      end
301
    end
302
    `WR_TOKEN_FF2_FIN:
303
    begin
304
      next_txDataWen <= 1'b0;
305
      NextState_rwBlkSt <= `WR_TOKEN_FE_ST;
306
    end
307
    `WR_TOKEN_FF2_ST:
308
    begin
309
      if (txDataFull == 1'b0)
310
      begin
311
        NextState_rwBlkSt <= `WR_TOKEN_FF2_FIN;
312
        next_txDataOut <= 8'hff;
313
        next_txDataWen <= 1'b1;
314
      end
315
    end
316
    `WR_TOKEN_FE_FIN:
317
    begin
318
      next_txDataWen <= 1'b0;
319
      NextState_rwBlkSt <= `WR_DATA_LOOP_INIT;
320
    end
321
    `WR_TOKEN_FE_ST:
322
    begin
323
      if (txDataFull == 1'b0)
324
      begin
325
        NextState_rwBlkSt <= `WR_TOKEN_FE_FIN;
326
        next_txDataOut <= 8'hfe;
327
        next_txDataWen <= 1'b1;
328
      end
329
    end
330
    `WR_BUSY_CHK_FIN:
331
    begin
332
      if (locRespByte == 8'h00 && timeOutCnt != `TWO_FIFTY_MS)
333
      begin
334
        NextState_rwBlkSt <= `WR_BUSY_SEND_CMD1;
335
        next_timeOutCnt <= timeOutCnt + 1'b1;
336
      end
337
      else if (timeOutCnt == `TWO_FIFTY_MS)
338
      begin
339
        NextState_rwBlkSt <= `WT_REQ;
340
        next_writeError <= `WRITE_BUSY_ERROR;
341
      end
342
      else
343
      begin
344
        NextState_rwBlkSt <= `WT_REQ;
345
      end
346
    end
347
    `WR_BUSY_WT_FIN1:
348
    begin
349
      if (rxDataRdy == 1'b1)
350
      begin
351
        NextState_rwBlkSt <= `WR_BUSY_CHK_FIN;
352
        next_locRespByte <= rxDataIn;
353
      end
354
    end
355
    `WR_BUSY_DEL1:
356
    begin
357
      next_txDataWen <= 1'b0;
358
      next_rxDataRdyClr <= 1'b0;
359
      next_delCnt1 <= delCnt1 + 1'b1;
360
      next_delCnt2 <= 8'h00;
361
      if (delCnt1 == `MAX_8_BIT)
362
      begin
363
        NextState_rwBlkSt <= `WR_BUSY_WT_FIN1;
364
      end
365
      else
366
      begin
367
        NextState_rwBlkSt <= `WR_BUSY_DEL2;
368
      end
369
    end
370
    `WR_BUSY_SEND_CMD1:
371
    begin
372
      next_txDataOut <= 8'hff;
373
      next_txDataWen <= 1'b1;
374
      next_rxDataRdyClr <= 1'b1;
375
      next_delCnt1 <= 8'h00;
376
      NextState_rwBlkSt <= `WR_BUSY_DEL1;
377
    end
378
    `WR_BUSY_DEL2:
379
    begin
380
      next_delCnt2 <= delCnt2 + 1'b1;
381
      if (delCnt2 == 8'hff)
382
      begin
383
        NextState_rwBlkSt <= `WR_BUSY_DEL1;
384
      end
385
    end
386
    `WR_BUSY_INIT_LOOP:
387
    begin
388
      next_timeOutCnt <= 12'h000;
389
      NextState_rwBlkSt <= `WR_BUSY_SEND_CMD1;
390
    end
391
    `RD_CMD_SEND_CMD:
392
    begin
393
      next_cmdByte <= 8'h51;
394
      //CMD17 Block Read
395
      next_dataByte1 <= blockAddr[31:24];
396
      next_dataByte2 <= blockAddr[23:16];
397
      next_dataByte3 <= blockAddr[15:8];
398
      next_dataByte4 <= blockAddr[7:0];
399
      next_checkSumByte <= 8'hff;
400
      next_sendCmdReq <= 1'b1;
401
      NextState_rwBlkSt <= `RD_CMD_DEL;
402
    end
403
    `RD_CMD_WT_FIN:
404
    begin
405
      if ((sendCmdRdy == 1'b1) && (respTout == 1'b1 || respByte != 8'h00))
406
      begin
407
        NextState_rwBlkSt <= `WT_REQ;
408
        next_readError <= `READ_CMD_ERROR;
409
      end
410
      else if (sendCmdRdy == 1'b1)
411
      begin
412
        NextState_rwBlkSt <= `RD_TOKEN_INIT_LOOP;
413
      end
414
    end
415
    `RD_CMD_DEL:
416
    begin
417
      next_sendCmdReq <= 1'b0;
418
      NextState_rwBlkSt <= `RD_CMD_WT_FIN;
419
    end
420
    `RD_TOKEN_CHK_LOOP:
421
    begin
422
      if (locRespByte != 8'hfe && timeOutCnt != `ONE_HUNDRED_MS)
423
      begin
424
        NextState_rwBlkSt <= `RD_TOKEN_DEL2;
425
        next_timeOutCnt <= timeOutCnt + 1'b1;
426
        next_delCnt1 <= 8'h00;
427
      end
428
      else if (timeOutCnt == `ONE_HUNDRED_MS)
429
      begin
430
        NextState_rwBlkSt <= `WT_REQ;
431
        next_readError <= `READ_TOKEN_ERROR;
432
      end
433
      else
434
      begin
435
        NextState_rwBlkSt <= `RD_DATA_CLR_RX;
436
        next_rxDataRdyClr <= 1'b1;
437
      end
438
    end
439
    `RD_TOKEN_WT_FIN:
440
    begin
441
      if (rxDataRdy == 1'b1)
442
      begin
443
        NextState_rwBlkSt <= `RD_TOKEN_CHK_LOOP;
444
        next_locRespByte <= rxDataIn;
445
      end
446
    end
447
    `RD_TOKEN_SEND_CMD:
448
    begin
449
      next_txDataOut <= 8'hff;
450
      next_txDataWen <= 1'b1;
451
      next_rxDataRdyClr <= 1'b1;
452
      NextState_rwBlkSt <= `RD_TOKEN_DEL1;
453
    end
454
    `RD_TOKEN_DEL2:
455
    begin
456
      next_delCnt1 <= delCnt1 + 1'b1;
457
      next_delCnt2 <= 8'h00;
458
      if (delCnt1 == `MAX_8_BIT)
459
      begin
460
        NextState_rwBlkSt <= `RD_TOKEN_SEND_CMD;
461
      end
462
      else
463
      begin
464
        NextState_rwBlkSt <= `RD_TOKEN_DEL3;
465
      end
466
    end
467
    `RD_TOKEN_INIT_LOOP:
468
    begin
469
      next_timeOutCnt <= 12'h000;
470
      NextState_rwBlkSt <= `RD_TOKEN_SEND_CMD;
471
    end
472
    `RD_TOKEN_DEL1:
473
    begin
474
      next_txDataWen <= 1'b0;
475
      next_rxDataRdyClr <= 1'b0;
476
      NextState_rwBlkSt <= `RD_TOKEN_WT_FIN;
477
    end
478
    `RD_TOKEN_DEL3:
479
    begin
480
      next_delCnt2 <= delCnt2 + 1'b1;
481
      if (delCnt2 == 8'hff)
482
      begin
483
        NextState_rwBlkSt <= `RD_TOKEN_DEL2;
484
      end
485
    end
486
    `RD_DATA_ST_LOOP:
487
    begin
488
      next_txDataWen <= 1'b1;
489
      next_txDataOut <= 8'hff;
490
      next_loopCnt <= loopCnt + 1'b1;
491
      NextState_rwBlkSt <= `RD_DATA_WT_DATA;
492
    end
493
    `RD_DATA_WT_DATA:
494
    begin
495
      next_txDataWen <= 1'b0;
496
      if (rxDataRdy == 1'b1)
497
      begin
498
        NextState_rwBlkSt <= `RD_DATA_CHK_LOOP;
499
        next_rxFifoWen <= 1'b1;
500
        next_rxDataRdyClr <= 1'b1;
501
        next_rxFifoData <= rxDataIn;
502
      end
503
    end
504
    `RD_DATA_CHK_LOOP:
505
    begin
506
      if (loopCnt == 9'b000000000)
507
      begin
508
        NextState_rwBlkSt <= `RD_DATA_CS_ST1;
509
        next_rxDataRdyClr <= 1'b0;
510
        next_rxFifoWen <= 1'b0;
511
      end
512
      else
513
      begin
514
        NextState_rwBlkSt <= `RD_DATA_ST_LOOP;
515
        next_rxDataRdyClr <= 1'b0;
516
        next_rxFifoWen <= 1'b0;
517
      end
518
    end
519
    `RD_DATA_CLR_RX:
520
    begin
521
      NextState_rwBlkSt <= `RD_DATA_ST_LOOP;
522
      next_rxDataRdyClr <= 1'b0;
523
      next_loopCnt <= 9'b000000000;
524
    end
525
    `RD_DATA_CS_FIN2:
526
    begin
527
      next_txDataWen <= 1'b0;
528
      if (txDataEmpty == 1'b1)
529
      begin
530
        NextState_rwBlkSt <= `WT_REQ;
531
      end
532
    end
533
    `RD_DATA_CS_FIN1:
534
    begin
535
      next_txDataWen <= 1'b0;
536
      NextState_rwBlkSt <= `RD_DATA_CS_ST2;
537
    end
538
    `RD_DATA_CS_ST1:
539
    begin
540
      if (txDataFull == 1'b0)
541
      begin
542
        NextState_rwBlkSt <= `RD_DATA_CS_FIN1;
543
        next_txDataOut <= 8'hff;
544
        next_txDataWen <= 1'b1;
545
      end
546
    end
547
    `RD_DATA_CS_ST2:
548
    begin
549
      if (txDataFull == 1'b0)
550
      begin
551
        NextState_rwBlkSt <= `RD_DATA_CS_FIN2;
552
        next_txDataOut <= 8'hff;
553
        next_txDataWen <= 1'b1;
554
      end
555
    end
556
    `WR_DATA_D_FIN:
557
    begin
558
      next_txDataWen <= 1'b0;
559
      if (loopCnt == 9'b000000000)
560
      begin
561
        NextState_rwBlkSt <= `WR_DATA_CS_ST1;
562
      end
563
      else
564
      begin
565
        NextState_rwBlkSt <= `WR_DATA_RD_FIFO1;
566
      end
567
    end
568
    `WR_DATA_D_ST:
569
    begin
570
      if (txDataFull == 1'b0)
571
      begin
572
        NextState_rwBlkSt <= `WR_DATA_D_FIN;
573
        next_txDataOut <= txFifoData;
574
        next_txDataWen <= 1'b1;
575
      end
576
    end
577
    `WR_DATA_RD_FIFO1:
578
    begin
579
      next_txFifoRen <= 1'b1;
580
      next_loopCnt <= loopCnt + 1'b1;
581
      NextState_rwBlkSt <= `WR_DATA_RD_FIFO2;
582
    end
583
    `WR_DATA_RD_FIFO2:
584
    begin
585
      next_txFifoRen <= 1'b0;
586
      NextState_rwBlkSt <= `WR_DATA_D_ST;
587
    end
588
    `WR_DATA_LOOP_INIT:
589
    begin
590
      next_loopCnt <= 9'b000000000;
591
      NextState_rwBlkSt <= `WR_DATA_RD_FIFO1;
592
    end
593
    `WR_DATA_CS_ST1:
594
    begin
595
      if (txDataFull == 1'b0)
596
      begin
597
        NextState_rwBlkSt <= `WR_DATA_CS_FIN1;
598
        next_txDataOut <= 8'hff;
599
        next_txDataWen <= 1'b1;
600
      end
601
    end
602
    `WR_DATA_CS_FIN1:
603
    begin
604
      next_txDataWen <= 1'b0;
605
      NextState_rwBlkSt <= `WR_DATA_CS_ST2;
606
    end
607
    `WR_DATA_CS_FIN2:
608
    begin
609
      next_txDataWen <= 1'b0;
610
      next_timeOutCnt <= 12'h000;
611
      if (txDataEmpty == 1'b1)
612
      begin
613
        NextState_rwBlkSt <= `WR_DATA_REQ_RESP_ST;
614
      end
615
    end
616
    `WR_DATA_CS_ST2:
617
    begin
618
      if (txDataFull == 1'b0)
619
      begin
620
        NextState_rwBlkSt <= `WR_DATA_CS_FIN2;
621
        next_txDataOut <= 8'hff;
622
        next_txDataWen <= 1'b1;
623
      end
624
    end
625
    `WR_DATA_CHK_RESP:
626
    begin
627
      if (timeOutCnt == `WR_RESP_TOUT)
628
      begin
629
        NextState_rwBlkSt <= `WT_REQ;
630
        next_writeError <= `WRITE_DATA_ERROR;
631
      end
632
      else if (locRespByte[4:0] == 5'h5)
633
      begin
634
        NextState_rwBlkSt <= `WR_BUSY_INIT_LOOP;
635
      end
636
      else
637
      begin
638
        NextState_rwBlkSt <= `WR_DATA_REQ_RESP_ST;
639
      end
640
    end
641
    `WR_DATA_REQ_RESP_ST:
642
    begin
643
      NextState_rwBlkSt <= `WR_DATA_DEL;
644
      next_txDataOut <= 8'hff;
645
      next_txDataWen <= 1'b1;
646
      next_timeOutCnt <= timeOutCnt + 1'b1;
647
      next_rxDataRdyClr <= 1'b1;
648
    end
649
    `WR_DATA_REQ_RESP_FIN:
650
    begin
651
      if (rxDataRdy == 1'b1)
652
      begin
653
        NextState_rwBlkSt <= `WR_DATA_CHK_RESP;
654
        next_locRespByte <= rxDataIn;
655
      end
656
    end
657
    `WR_DATA_DEL:
658
    begin
659
      NextState_rwBlkSt <= `WR_DATA_REQ_RESP_FIN;
660
      next_txDataWen <= 1'b0;
661
      next_rxDataRdyClr <= 1'b0;
662
    end
663
  endcase
664
end
665
 
666
// Current State Logic (sequential)
667
always @ (posedge clk)
668
begin
669
  if (rst == 1'b1)
670
    CurrState_rwBlkSt <= `ST_RW_SD;
671
  else
672
    CurrState_rwBlkSt <= NextState_rwBlkSt;
673
end
674
 
675
// Registered outputs logic
676
always @ (posedge clk)
677
begin
678
  if (rst == 1'b1)
679
  begin
680
    readWriteSDBlockRdy <= 1'b0;
681
    spiCS_n <= 1'b1;
682
    readError <= 1'b0;
683
    writeError <= 1'b0;
684
    txDataOut <= 8'h00;
685
    txDataWen <= 1'b0;
686
    rxDataRdyClr <= 1'b0;
687
    cmdByte <= 8'h00;
688
    dataByte1 <= 8'h00;
689
    dataByte2 <= 8'h00;
690
    dataByte3 <= 8'h00;
691
    dataByte4 <= 8'h00;
692
    checkSumByte <= 8'h00;
693
    sendCmdReq <= 1'b0;
694
    txFifoRen <= 1'b0;
695
    rxFifoWen <= 1'b0;
696
    rxFifoData <= 8'h00;
697
    loopCnt <= 8'h00;
698
    delCnt1 <= 8'h00;
699
    delCnt2 <= 8'h00;
700
    timeOutCnt <= 12'h000;
701
    locRespByte <= 8'h00;
702
  end
703
  else
704
  begin
705
    readWriteSDBlockRdy <= next_readWriteSDBlockRdy;
706
    spiCS_n <= next_spiCS_n;
707
    readError <= next_readError;
708
    writeError <= next_writeError;
709
    txDataOut <= next_txDataOut;
710
    txDataWen <= next_txDataWen;
711
    rxDataRdyClr <= next_rxDataRdyClr;
712
    cmdByte <= next_cmdByte;
713
    dataByte1 <= next_dataByte1;
714
    dataByte2 <= next_dataByte2;
715
    dataByte3 <= next_dataByte3;
716
    dataByte4 <= next_dataByte4;
717
    checkSumByte <= next_checkSumByte;
718
    sendCmdReq <= next_sendCmdReq;
719
    txFifoRen <= next_txFifoRen;
720
    rxFifoWen <= next_rxFifoWen;
721
    rxFifoData <= next_rxFifoData;
722
    loopCnt <= next_loopCnt;
723
    delCnt1 <= next_delCnt1;
724
    delCnt2 <= next_delCnt2;
725
    timeOutCnt <= next_timeOutCnt;
726
    locRespByte <= next_locRespByte;
727
  end
728
end
729
 
730
endmodule

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