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dualflexpress.v
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dualflexpress.v
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////////////////////////////////////////////////////////////////////////////////
//
// Filename: dualflexpress.v
// {{{
// Project: A Set of Wishbone Controlled SPI Flash Controllers
//
// Purpose: To provide wishbone controlled read access (and read access
// *only*) to the DSPI flash, using a flash clock equal to the
// system clock, and nothing more. Indeed, this is designed to be a
// *very* stripped down version of a flash driver, with the goal of
// providing 1) very fast access for 2) very low logic count.
//
// Three modes/states of operation:
// 1. Startup/maintenance, places the device in the dual XIP mode
// 2. Normal operations, takes 33 clocks to read a value
// - 16 subsequent clocks will read a piped value
// 3. Configuration--useful to allow an external controller issue erase
// or program commands (or other) without requiring us to
// clutter up the logic with a giant state machine
//
// STARTUP
// 1. Waits for the flash to come on line
// Start out idle for 300 uS
// 2. Sends a signal to remove the flash from any DSPI read mode. In our
// case, we'll send several clocks of an empty command. In SPI
// mode, it'll get ignored. In QSPI mode, it'll remove us from
// DSPI mode.
// 3. Explicitly places and leaves the flash into DSPI mode
// 0xEB 3(0xa0) 0xa0 0xa0 0xa0 4(0x00)
// 4. All done
//
// Creator: Dan Gisselquist, Ph.D.
// Gisselquist Technology, LLC
//
////////////////////////////////////////////////////////////////////////////////
// }}}
// Copyright (C) 2018-2021, Gisselquist Technology, LLC
// {{{
// This file is part of the set of Wishbone controlled SPI flash controllers
// project
//
// The Wishbone SPI flash controller project is free software (firmware):
// 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 3 of the License, or (at your option) any later version.
//
// The Wishbone SPI flash controller project is distributed in the hope
// that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
// warranty of MERCHANTIBILITY 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 program. (It's in the $(ROOT)/doc directory. Run make
// with no target there if the PDF file isn't present.) If not, see
// <http://www.gnu.org/licenses/> for a copy.
// }}}
// License: LGPL, v3, as defined and found on www.gnu.org,
// {{{
// http://www.gnu.org/licenses/lgpl.html
//
//
////////////////////////////////////////////////////////////////////////////////
//
//
`default_nettype none
// }}}
// 290 raw, 372 w/ pipe, 410 cfg, 499 cfg w/pipe
module dualflexpress #(
// {{{
// LGFLASHSZ
// {{{
// LGFLASHSZ is the size of the flash memory. It defines the
// number of bits in the address register and more. This
// controller will support flash sizes up to 2^LGFLASHSZ,
// where LGFLASHSZ goes up to 32.
parameter LGFLASHSZ=24,
// }}}
// OPT_PIPE
// {{{
// OPT_PIPE makes it possible to string multiple requests
// together, with no intervening need to shutdown the QSPI
// connection and send a new address
parameter [0:0] OPT_PIPE = 1'b1,
// }}}
// OPT_CFG
// {{{
// OPT_CFG enables the configuration logic port, and hence the
// ability to erase and program the flash, as well as the
// ability to perform other commands such as read-manufacturer
// ID, adjust configuration registers, etc.
parameter [0:0] OPT_CFG = 1'b1,
// }}}
// OPT_STARTUP enables the startup logic
// {{{
parameter [0:0] OPT_STARTUP = 1'b1,
// }}}
// OPT_ADDR32
// {{{
// OPT_ADDR32 enables 32 bit addressing, rather than 24bit
// Control this by controlling the LGFLASHSZ parameter above.
// Anything greater than 24 will use 32-bit addressing,
// otherwise the regular 24-bit addressing
localparam [0:0] OPT_ADDR32 = (LGFLASHSZ > 24),
// }}}
// OPT_CLKDIV
// {{{
parameter OPT_CLKDIV = 0,
// }}}
// OPT_ENDIANSWAP
// {{{
// Normally, I place the first byte read from the flash, and
// the lowest flash address, into bits [7:0], and then shift
// it up--to where upon return it is found in bits [31:24].
// This is ideal for a big endian systems, not so much for
// little endian systems. The endian swap allows the bus to
// swap the return values in order to support little endian
// systems.
parameter [0:0] OPT_ENDIANSWAP = 1'b1,
// }}}
// OPT_ODDR
// {{{
// OPT_ODDR will be true any time the clock has no clock
// division
localparam [0:0] OPT_ODDR = (OPT_CLKDIV == 0),
// }}}
// CKDV_BITS
// {{{
// CKDV_BITS is the number of bits necessary to represent a
// counter that can do the CLKDIV division
localparam CKDV_BITS = (OPT_CLKDIV == 0) ? 0
: ((OPT_CLKDIV < 2) ? 1
: ((OPT_CLKDIV < 4) ? 2
: ((OPT_CLKDIV < 8) ? 3
: ((OPT_CLKDIV < 16) ? 4
: ((OPT_CLKDIV < 32) ? 5
: ((OPT_CLKDIV < 64) ? 6
: ((OPT_CLKDIV < 128) ? 7
: ((OPT_CLKDIV < 256) ? 8 : 9)))))))),
// }}}
// RDDELAY
// {{{
// RDDELAY is the number of clock cycles from when o_dspi_dat
// is valid until i_dspi_dat is valid. Read delays from 0-4
// have been verified. DDR Registered I/O on a Xilinx device
// can be done with a RDDELAY=3. On Intel/Altera devices,
// RDDELAY=2 works. I'm using RDDELAY=0 for my iCE40 devices
parameter RDDELAY = 0,
// }}}
// NDUMMY
// {{{
// NDUMMY is the number of "dummy" clock cycles between the
// 24-bits of the Quad I/O address and the first data bits.
// This includes the two clocks of the Quad output mode byte,
// 0xa0. The default is 10 for a Micron device. Windbond
// seems to want 2. Note your flash device carefully when
// you choose this value.
parameter NDUMMY = 8,
// }}}
// OPT_STARTUP_FILE
// {{{
// For dealing with multiple flash devices, the
// OPT_STARTUP_FILE allows a hex file to be provided containing
// the necessary script to place the design into the proper
// initial configuration
parameter OPT_STARTUP_FILE="",
// }}}
//
//
//
localparam [4:0] CFG_MODE = 12,
localparam [4:0] QSPEED_BIT = 11, // Not supported
localparam [4:0] DSPEED_BIT = 10,
localparam [4:0] DIR_BIT = 9,
localparam [4:0] USER_CS_n = 8,
//
localparam [1:0] NORMAL_SPI = 2'b00,
localparam [1:0] DUAL_WRITE = 2'b10,
localparam [1:0] DUAL_READ = 2'b11,
localparam [7:0] DIO_READ_CMD = 8'hbb,
//
localparam AW=LGFLASHSZ-2,
localparam DW=32
//
`ifdef FORMAL
, localparam F_LGDEPTH=$clog2(12+16+1+NDUMMY+RDDELAY+(OPT_ADDR32 ? 4:0))
// reg f_past_valid;
`endif
// }}}
) (
// {{{
input wire i_clk, i_reset,
//
input wire i_wb_cyc, i_wb_stb, i_cfg_stb, i_wb_we,
input wire [(AW-1):0] i_wb_addr,
input wire [(DW-1):0] i_wb_data,
//
output reg o_wb_ack, o_wb_stall,
output reg [(DW-1):0] o_wb_data,
//
output reg o_dspi_sck,
output reg o_dspi_cs_n,
output reg [1:0] o_dspi_mod,
output wire [1:0] o_dspi_dat,
input wire [1:0] i_dspi_dat,
// Debugging port
output wire o_dbg_trigger,
output wire [31:0] o_debug
// }}}
);
// Signal declarations
// {{{
`ifdef FORMAL
reg f_past_valid;
`endif
reg dly_ack, read_sck, xtra_stall;
// clk_ctr must have enough bits for ...
// 12 address clocks, 2-bits each
// 4 extra address clocks, for 32bit addressing
// NDUMMY dummy clocks, including two mode bytes
// 16 data clocks
// (RDDELAY clocks not counted here)
reg [5:0] clk_ctr;
//
// User override logic
//
reg cfg_mode, cfg_speed, cfg_dir, cfg_cs;
wire cfg_write, cfg_hs_write, cfg_ls_write, cfg_hs_read,
user_request, bus_request, pipe_req, cfg_noop, cfg_stb;
//
assign bus_request = (i_wb_stb)&&(!o_wb_stall)
&&(!i_wb_we)&&(!cfg_mode);
assign cfg_stb = (OPT_CFG)&&(i_cfg_stb)&&(!o_wb_stall);
assign cfg_noop = ((cfg_stb)&&((!i_wb_we)||(!i_wb_data[CFG_MODE])
||(i_wb_data[USER_CS_n])))
||((!OPT_CFG)&&(i_cfg_stb)&&(!o_wb_stall));
assign user_request = (cfg_stb)&&(i_wb_we)&&(i_wb_data[CFG_MODE]);
assign cfg_write = (user_request)&&(!i_wb_data[USER_CS_n]);
assign cfg_hs_write = (cfg_write)&&(i_wb_data[DSPEED_BIT])
&&(i_wb_data[DIR_BIT]);
assign cfg_hs_read = (cfg_write)&&(i_wb_data[DSPEED_BIT])
&&(!i_wb_data[DIR_BIT]);
assign cfg_ls_write = (cfg_write)&&(!i_wb_data[DSPEED_BIT]);
reg ckstb, ckpos, ckneg, ckpre;
reg maintenance;
reg [1:0] m_mod;
reg m_cs_n;
reg m_clk;
reg [1:0] m_dat;
reg [32+(OPT_ADDR32 ? 8:0)+2*(OPT_ODDR ? 0:1)-1:0] data_pipe;
reg pre_ack = 1'b0;
reg actual_sck;
reg r_last_cfg;
// }}}
////////////////////////////////////////////////////////////////////////
//
// Clock division
// {{{
////////////////////////////////////////////////////////////////////////
//
// ckstb, ckpos, ckneg, ckpre
// {{{
generate if (OPT_ODDR)
begin
// {{{
always @(*)
begin
ckstb = 1'b1;
ckpos = 1'b1;
ckneg = 1'b1;
ckpre = 1'b1;
end
// }}}
end else if (OPT_CLKDIV == 1)
begin : CKSTB_ONE
// {{{
reg clk_counter;
initial clk_counter = 1'b1;
always @(posedge i_clk)
if (i_reset)
clk_counter <= 1'b1;
else if (clk_counter != 0)
clk_counter <= 1'b0;
else if (bus_request)
clk_counter <= (pipe_req);
else if ((maintenance)||(!o_dspi_cs_n && o_wb_stall))
clk_counter <= 1'b1;
always @(*)
begin
ckpre = (clk_counter == 1);
ckstb = (clk_counter == 0);
ckpos = (clk_counter == 1);
ckneg = (clk_counter == 0);
end
// }}}
end else begin : CKSTB_GEN
// {{{
reg [CKDV_BITS-1:0] clk_counter;
initial clk_counter = OPT_CLKDIV;
always @(posedge i_clk)
if (i_reset)
clk_counter <= OPT_CLKDIV;
else if (clk_counter != 0)
clk_counter <= clk_counter - 1;
else if (bus_request)
clk_counter <= (pipe_req ? OPT_CLKDIV : 0);
else if ((maintenance)||(!o_dspi_cs_n && o_wb_stall))
clk_counter <= OPT_CLKDIV;
initial ckpre = (OPT_CLKDIV == 1);
initial ckstb = 1'b0;
initial ckpos = (OPT_CLKDIV == 1);
always @(posedge i_clk)
if (i_reset)
begin
ckpre <= (OPT_CLKDIV == 1);
ckstb <= 1'b0;
ckpos <= (OPT_CLKDIV == 1);
end else // if (OPT_CLKDIV > 1)
begin
ckpre <= (clk_counter == 2);
ckstb <= (clk_counter == 1);
ckpos <= (clk_counter == (OPT_CLKDIV+1)/2+1);
end
always @(*)
ckneg = ckstb;
`ifdef FORMAL
// {{{
always @(*)
assert(!ckpos || !ckneg);
always @(posedge i_clk)
if ((f_past_valid)&&(!$past(i_reset))&&($past(ckpre)))
assert(ckstb);
// }}}
`endif
// }}}
end endgenerate
// }}}
// }}}
////////////////////////////////////////////////////////////////////////
//
// Startup logic
// {{{
////////////////////////////////////////////////////////////////////////
//
//
//
generate if (OPT_STARTUP)
begin : GEN_STARTUP
// {{{
localparam M_WAITBIT=10;
localparam M_LGADDR=5;
`ifdef FORMAL
// For formal, jump into the middle of the startup
localparam M_FIRSTIDX=9;
`else
localparam M_FIRSTIDX=0;
`endif
reg [M_WAITBIT:0] m_this_word;
reg [M_WAITBIT:0] m_cmd_word [0:(1<<M_LGADDR)-1];
reg [M_LGADDR-1:0] m_cmd_index;
reg [M_WAITBIT-1:0] m_counter;
reg m_midcount;
reg [3:0] m_bitcount;
reg [7:0] m_byte;
// Let's script our startup with a series of commands.
//
// The format of the data words is ...
// 1'bit (MSB) to indicate this is a counter word.
// Counter words count a number of idle cycles,
// in which the port is unused (CSN is high)
//
// 2'bit mode. This is either ...
// NORMAL_SPI, for a normal SPI interaction:
// MOSI, MISO, WPn and HOLD
// DUAL_READ, both data pins set as inputs. In this
// startup, the input values will be
// ignored.
// or DUAL_WRITE, both pins are outputs. This is
// important for getting the flash into
// an XIP mode that we can then use for
// all reads following.
//
// 8'bit data To be sent 1-bit at a time in NORMAL_SPI
// mode, or 4-bits at a time in DUAL_WRITE
// mode. Ignored otherwis
//
integer k;
initial begin
for(k=0; k<(1<<M_LGADDR); k=k+1)
m_cmd_word[k] = -1;
// cmd_word= m_ctr_flag, m_mod[1:0],
// m_cs_n, m_clk, m_data[3:0]
// Start off idle
// This is really redundant since all of our commands are
// idle's.
m_cmd_word[5'h0a] = -1;
//
// Since we don't know what mode we started in, whether the
// device was left in XIP mode or some other mode, we'll start
// by exiting any mode we might have been in.
//
// The key to doing this is to issue a non-command, that can
// also be interpreted as an XIP address with an incorrect
// mode bit. That will get us out of any XIP mode, and back
// into a SPI mode we might use. The command is issued in
// NORMAL_SPI mode, however, since we don't know if the device
// is initially in XIP or not.
//
// The following is for WINBOND
//
// Exit any QSPI mode we might've been in
m_cmd_word[5'h0f] = { 1'b0, NORMAL_SPI, 8'hff }; // Addr 1-2
m_cmd_word[5'h10] = { 1'b0, NORMAL_SPI, 8'hff }; // Addr 3-Mode
m_cmd_word[5'h11] = { 1'b0, NORMAL_SPI, 8'hff }; // Extra
// Idle
m_cmd_word[5'h12] = { 1'b1, 10'h3f };
// Idle
// Enter into QSPI mode, 0xeb, 0,0,0
// 0xeb
m_cmd_word[5'h13] = { 1'b0, NORMAL_SPI, DIO_READ_CMD };
// Addr #1
m_cmd_word[5'h14] = { 1'b0, DUAL_WRITE, 8'h01 };
// Addr #2
m_cmd_word[5'h15] = { 1'b0, DUAL_WRITE, 8'h20 };
// Addr #3
m_cmd_word[5'h16] = { 1'b0, DUAL_WRITE, 8'h48 };
// Mode byte
m_cmd_word[5'h17] = { 1'b0, DUAL_WRITE, 8'ha0 };
// Dummy clocks, x10 for this flash
m_cmd_word[5'h18] = { 1'b0, DUAL_WRITE, 8'h00 };
m_cmd_word[5'h19] = { 1'b0, DUAL_WRITE, 8'h00 };
m_cmd_word[5'h1a] = { 1'b0, DUAL_WRITE, 8'h00 };
m_cmd_word[5'h1b] = { 1'b0, DUAL_WRITE, 8'h00 };
m_cmd_word[5'h1c] = { 1'b0, DUAL_WRITE, 8'h00 };
// Now read a byte for form
m_cmd_word[5'h1d] = { 1'b0, DUAL_READ, 8'h00 };
// Idle
m_cmd_word[5'h1e] = -1;
m_cmd_word[5'h1f] = -1;
// Then we are in business!
end
reg m_final;
wire m_ce, new_word;
assign m_ce = (!m_midcount)&&(ckstb);
assign new_word = (m_ce && m_bitcount == 0);
//
initial maintenance = 1'b1;
initial m_cmd_index = M_FIRSTIDX;
always @(posedge i_clk)
if (i_reset)
begin
m_cmd_index <= M_FIRSTIDX;
maintenance <= 1'b1;
end else if (new_word)
begin
maintenance <= (maintenance)&&(!m_final);
if (!(&m_cmd_index))
m_cmd_index <= m_cmd_index + 1'b1;
end
initial m_this_word = -1;
always @(posedge i_clk)
if (new_word)
m_this_word <= m_cmd_word[m_cmd_index];
initial m_final = 1'b0;
always @(posedge i_clk)
if (i_reset)
m_final <= 1'b0;
else if (new_word)
m_final <= (m_final || (&m_cmd_index));
//
// m_midcount .. are we in the middle of a counter/pause?
//
initial m_midcount = 1;
initial m_counter = -1;
always @(posedge i_clk)
if (i_reset)
begin
m_midcount <= 1'b1;
`ifdef FORMAL
m_counter <= 3;
`else
m_counter <= -1;
`endif
end else if (new_word)
begin
m_midcount <= m_this_word[M_WAITBIT]
&& (|m_this_word[M_WAITBIT-1:0]);
if (m_this_word[M_WAITBIT])
begin
m_counter <= m_this_word[M_WAITBIT-1:0];
`ifdef FORMAL
if (m_this_word[M_WAITBIT-1:0] > 3)
m_counter <= 3;
`endif
end
end else begin
m_midcount <= (m_counter > 1);
if (m_counter > 0)
m_counter <= m_counter - 1'b1;
end
initial m_cs_n = 1'b1;
initial m_mod = NORMAL_SPI;
always @(posedge i_clk)
if (i_reset)
begin
m_cs_n <= 1'b1;
m_mod <= NORMAL_SPI;
m_bitcount <= 0;
end else if (ckstb)
begin
if (m_bitcount != 0)
m_bitcount <= m_bitcount - 1;
else if ((m_ce)&&(m_final))
begin
m_cs_n <= 1'b1;
m_mod <= NORMAL_SPI;
m_bitcount <= 0;
end else if ((m_midcount)||(m_this_word[M_WAITBIT]))
begin
m_cs_n <= 1'b1;
m_mod <= NORMAL_SPI;
m_bitcount <= 0;
end else begin
m_cs_n <= 1'b0;
m_mod <= m_this_word[M_WAITBIT-1:M_WAITBIT-2];
m_bitcount <= (!OPT_ODDR && m_cs_n) ? 4'h4 : 4'h3;
if (!m_this_word[M_WAITBIT-1])
m_bitcount <= (!OPT_ODDR && m_cs_n) ? 4'h8 : 4'h7;//i.e.7
end
end
always @(posedge i_clk)
if (m_ce)
begin
if (m_bitcount == 0)
begin
if (!OPT_ODDR && m_cs_n)
begin
m_dat <= {(2){m_this_word[7]}};
m_byte <= m_this_word[7:0];
end else begin
m_dat <= m_this_word[7:6];
m_byte <= { m_this_word[5:0],2'b00};
if (!m_this_word[M_WAITBIT-1])
begin
// Slow speed
m_dat[0] <= m_this_word[7];
m_byte <= {m_this_word[6:0],1'b0};
end
end
end else begin
m_dat <= m_byte[7:6];
if (!m_mod[1])
begin
// Slow speed
m_dat[0] <= m_byte[7];
m_byte <= { m_byte[6:0], 1'b0 };
end else begin
m_byte <= { m_byte[5:0], 2'b00 };
end
end
end
if (OPT_ODDR)
begin
always @(*)
m_clk = !m_cs_n;
end else begin
always @(posedge i_clk)
if (i_reset)
m_clk <= 1'b1;
else if (m_cs_n)
m_clk <= 1'b1;
else if ((!m_clk)&&(ckpos))
m_clk <= 1'b1;
else if (m_midcount)
m_clk <= 1'b1;
else if (new_word && m_this_word[M_WAITBIT])
m_clk <= 1'b1;
else if (ckneg)
m_clk <= 1'b0;
end
`ifdef FORMAL
// {{{
(* anyconst *) reg [M_LGADDR:0] f_const_addr;
always @(*)
begin
assert((m_cmd_word[f_const_addr][M_WAITBIT])
||(m_cmd_word[f_const_addr][9:8] != 2'b01));
if (m_cmd_word[f_const_addr][M_WAITBIT])
assert(m_cmd_word[f_const_addr][M_WAITBIT-3:0] > 0);
end
always @(*)
begin
if (m_cmd_index != f_const_addr)
assume((m_cmd_word[m_cmd_index][M_WAITBIT])||(m_cmd_word[m_cmd_index][9:8] != 2'b01));
if (m_cmd_word[m_cmd_index][M_WAITBIT])
assume(m_cmd_word[m_cmd_index][M_WAITBIT-3:0]>0);
end
always @(*)
begin
assert((m_this_word[M_WAITBIT])
||(m_this_word[9:8] != 2'b01));
if (m_this_word[M_WAITBIT])
assert(m_this_word[M_WAITBIT-3:0] > 0);
end
// Setting the last two command words to IDLE with maximum
// counts is required by our implementation
always @(*)
assert(m_cmd_word[5'h1e] == 11'h7ff);
always @(*)
assert(m_cmd_word[5'h1f] == 11'h7ff);
wire [M_LGADDR-1:0] last_index;
assign last_index = m_cmd_index - 1;
always @(posedge i_clk)
if ((f_past_valid)&&(m_cmd_index != M_FIRSTIDX))
assert(m_this_word == m_cmd_word[last_index]);
always @(posedge i_clk)
assert(m_midcount == (m_counter != 0));
always @(posedge i_clk)
begin
cover(!maintenance);
cover(m_cmd_index == 5'h0a);
cover(m_cmd_index == 5'h0b);
cover(m_cmd_index == 5'h0c);
cover(m_cmd_index == 5'h0d);
cover(m_cmd_index == 5'h0e);
cover(m_cmd_index == 5'h0f);
cover(m_cmd_index == 5'h10);
cover(m_cmd_index == 5'h11);
cover(m_cmd_index == 5'h12);
cover(m_cmd_index == 5'h13);
cover(m_cmd_index == 5'h14);
cover(m_cmd_index == 5'h15);
cover(m_cmd_index == 5'h16);
cover(m_cmd_index == 5'h17);
cover(m_cmd_index == 5'h18);
cover(m_cmd_index == 5'h19);
cover(m_cmd_index == 5'h1a);
cover(m_cmd_index == 5'h1b);
cover(m_cmd_index == 5'h1c);
cover(m_cmd_index == 5'h1d);
cover(m_cmd_index == 5'h1e);
cover(m_cmd_index == 5'h1f);
end
reg [M_WAITBIT:0] f_last_word;
reg [8:0] f_mspi;
reg [4:0] f_mdspi;
initial f_last_word = -1;
always @(posedge i_clk)
if (i_reset)
f_last_word = -1;
else if (new_word)
f_last_word <= m_this_word;
initial f_mspi = 0;
always @(posedge i_clk)
if (i_reset)
f_mspi <= 0;
else if (ckstb) begin
f_mspi <= f_mspi << 1;
if (maintenance && !m_final && new_word
&&(!m_this_word[M_WAITBIT])
&&(m_this_word[9:8] == NORMAL_SPI))
begin
if (m_cs_n && !OPT_ODDR)
f_mspi[0] <= 1'b1;
else
f_mspi[1] <= 1'b1;
end
end
initial f_mdspi = 0;
always @(posedge i_clk)
if (i_reset)
f_mdspi <= 0;
else if (ckstb) begin
f_mdspi <= f_mdspi << 1;
if (maintenance && !m_final && new_word
&&(!m_this_word[M_WAITBIT])
&&(m_this_word[9]))
begin
if (m_cs_n && !OPT_ODDR)
f_mdspi[0] <= 1'b1;
else
f_mdspi[1] <= 1'b1;
end
end
always @(*)
if (OPT_ODDR)
assert(!f_mspi[0] && !f_mdspi[0]);
always @(*)
if ((|f_mspi) || (|f_mdspi))
begin
assert(maintenance);
assert(!m_cs_n);
assert(m_mod == f_last_word[9:8]);
assert(m_midcount == 1'b0);
end else if (maintenance && m_cs_n)
begin
assert(f_last_word[M_WAITBIT]);
assert(m_counter <= f_last_word[M_WAITBIT-1:0]);
assert(m_midcount == (m_counter != 0));
assert(m_cs_n);
end
always @(*)
assert((f_mspi == 0)||(f_mdspi == 0));
always @(*)
if (|f_mspi)
assert(m_mod == NORMAL_SPI);
always @(*)
case(f_mspi[8:1])
8'h00: begin end
8'h01: assert(m_dat[0] == f_last_word[7]);
8'h02: assert(m_dat[0] == f_last_word[6]);
8'h04: assert(m_dat[0] == f_last_word[5]);
8'h08: assert(m_dat[0] == f_last_word[4]);
8'h10: assert(m_dat[0] == f_last_word[3]);
8'h20: assert(m_dat[0] == f_last_word[2]);
8'h40: assert(m_dat[0] == f_last_word[1]);
8'h80: assert(m_dat[0] == f_last_word[0]);
default: begin assert(0); end
endcase
always @(*)
if (|f_mdspi)
assert(m_mod == DUAL_WRITE || m_mod == DUAL_READ);
always @(*)
case(f_mdspi[4:1])
4'b0000: begin end
4'b0001: assert(m_dat[1:0] == f_last_word[7:6]);
4'b0010: assert(m_dat[1:0] == f_last_word[5:4]);
4'b0100: assert(m_dat[1:0] == f_last_word[3:2]);
4'b1000: assert(m_dat[1:0] == f_last_word[1:0]);
default: begin assert(0); end
endcase
// }}}
`endif
// }}}
end else begin : NO_STARTUP_OPT
// {{{
always @(*)
begin
maintenance = 0;
m_mod = 2'b00;
m_cs_n = 1'b1;
m_clk = 1'b0;
m_dat = 2'h0;
end
// verilator lint_off UNUSED
wire unused_maintenance;
assign unused_maintenance = &{ 1'b0, maintenance,
m_mod, m_cs_n, m_clk, m_dat };
// verilator lint_on UNUSED
// }}}
end endgenerate
// }}}
////////////////////////////////////////////////////////////////////////
//
// Data / access logic
// {{{
////////////////////////////////////////////////////////////////////////
//
//
// data_pipe
// {{{
initial data_pipe = 0;
always @(posedge i_clk)
begin
if (!o_wb_stall)
begin
// Set the high bits to zero initially
data_pipe <= 0;
data_pipe[8+LGFLASHSZ-1:0] <= {
i_wb_addr, 2'b00, 4'ha, 4'h0 };
if (i_cfg_stb)
// High speed configuration I/O
data_pipe[24+(OPT_ADDR32 ? 8:0) +: 8] <= i_wb_data[7:0];
if ((i_cfg_stb)&&(!i_wb_data[DSPEED_BIT]))
begin // Low speed configuration I/O
data_pipe[30+(OPT_ADDR32 ? 8:0)]<= i_wb_data[7];
data_pipe[28+(OPT_ADDR32 ? 8:0)]<= i_wb_data[6];
data_pipe[26+(OPT_ADDR32 ? 8:0)]<= i_wb_data[5];
data_pipe[24+(OPT_ADDR32 ? 8:0)]<= i_wb_data[4];
end
if (i_cfg_stb)
begin // These can be set independent of speed
data_pipe[22+(OPT_ADDR32 ? 8:0)] <= i_wb_data[3];
data_pipe[20+(OPT_ADDR32 ? 8:0)] <= i_wb_data[2];
data_pipe[18+(OPT_ADDR32 ? 8:0)] <= i_wb_data[1];
data_pipe[16+(OPT_ADDR32 ? 8:0)] <= i_wb_data[0];
end
end else if (ckstb)
data_pipe <= { data_pipe[(32+(OPT_ADDR32 ? 8:0)+2*((OPT_ODDR ? 0:1)-1))-1:0], 2'h0 };
if (maintenance)
data_pipe[30+(OPT_ADDR32 ? 8:0)+2*(OPT_ODDR ? 0:1) +: 2] <= m_dat;
end
// }}}
assign o_dspi_dat = data_pipe[30+(OPT_ADDR32 ? 8:0)+2*(OPT_ODDR ? 0:1) +: 2];
// pre_ack
// {{{
// Since we can't abort any transaction once started, without
// risking losing XIP mode or any other mode we might be in, we'll
// keep track of whether this operation should be ack'd upon
// completion
always @(posedge i_clk)
if ((i_reset)||(!i_wb_cyc))
pre_ack <= 1'b0;
else if ((bus_request)||(cfg_write))
pre_ack <= 1'b1;
// }}}
// pipe_req
// {{{
generate if (OPT_PIPE)
begin : OPT_PIPE_BLOCK
// {{{
reg r_pipe_req;
wire w_pipe_condition;
reg [(AW-1):0] next_addr;
// {{{
always @(posedge i_clk)
if (!o_wb_stall)
next_addr <= i_wb_addr + 1'b1;
// }}}
// w_pipe_condition
// {{{
assign w_pipe_condition = (i_wb_stb)&&(!i_wb_we)&&(pre_ack)
&&(!maintenance)
&&(!cfg_mode)
&&(!o_dspi_cs_n)
&&(|clk_ctr[2:0])
&&(next_addr == i_wb_addr);
// }}}
// r_pipe_req
// {{{
initial r_pipe_req = 1'b0;
always @(posedge i_clk)
if ((clk_ctr == 1)&&(ckstb))
r_pipe_req <= 1'b0;
else
r_pipe_req <= w_pipe_condition;
// }}}
assign pipe_req = r_pipe_req;
// }}}
end else begin
assign pipe_req = 1'b0;
end endgenerate
// }}}
// clk_ctr
// {{{
initial clk_ctr = 0;
always @(posedge i_clk)
if ((i_reset)||(maintenance))
clk_ctr <= 0;
else if ((bus_request)&&(!pipe_req))
// Notice that this is only for
// regular bus reads, and so the check for
// !pipe_req
clk_ctr <= 6'd12+6'd16+NDUMMY + (OPT_ADDR32 ? 4:0)+(OPT_ODDR ? 0:1);
else if (bus_request) // && pipe_req
// Otherwise, if this is a piped read, we'll
// reset the counter back to eight.
clk_ctr <= 6'd16;
else if (cfg_ls_write)
clk_ctr <= 6'd8 + ((OPT_ODDR) ? 0:1);
else if (cfg_write)
clk_ctr <= 6'd4 + ((OPT_ODDR) ? 0:1);
else if ((ckstb)&&(|clk_ctr))
clk_ctr <= clk_ctr - 1'b1;
// }}}
// o_dspi_sck
// {{{
initial o_dspi_sck = (!OPT_ODDR);
always @(posedge i_clk)
if (i_reset)
o_dspi_sck <= (!OPT_ODDR);
else if (maintenance)
o_dspi_sck <= m_clk;
else if ((!OPT_ODDR)&&(bus_request)&&(pipe_req))
o_dspi_sck <= 1'b0;
else if ((bus_request)||(cfg_write))
o_dspi_sck <= 1'b1;
else if (OPT_ODDR)
begin
// {{{
if ((cfg_mode)&&(clk_ctr <= 1))
// Config mode has no pipe instructions
o_dspi_sck <= 1'b0;
else if (clk_ctr[5:0] > 6'd1)
o_dspi_sck <= 1'b1;
else
o_dspi_sck <= 1'b0;
// }}}
end else if (((ckpos)&&(!o_dspi_sck))||(o_dspi_cs_n))
begin
o_dspi_sck <= 1'b1;
end else if ((ckneg)&&(o_dspi_sck))
begin
// {{{
if ((cfg_mode)&&(clk_ctr <= 1))
// Config mode has no pipe instructions
o_dspi_sck <= 1'b1;
else if (clk_ctr[5:0] > 6'd1)
o_dspi_sck <= 1'b0;
else
o_dspi_sck <= 1'b1;
// }}}
end
// }}}
// o_dspi_cs_n
// {{{
initial o_dspi_cs_n = 1'b1;
always @(posedge i_clk)
if (i_reset)
o_dspi_cs_n <= 1'b1;
else if (maintenance)
o_dspi_cs_n <= m_cs_n;
else if ((cfg_stb)&&(i_wb_we))
o_dspi_cs_n <= (!i_wb_data[CFG_MODE])||(i_wb_data[USER_CS_n]);
else if ((OPT_CFG)&&(cfg_cs))
o_dspi_cs_n <= 1'b0;
else if ((bus_request)||(cfg_write))
o_dspi_cs_n <= 1'b0;
else if (ckstb)
o_dspi_cs_n <= (clk_ctr <= 1);
// }}}
// o_dspi_mod -- controlling the mode of the external pins
// {{{
// Control the mode of the external pins
// NORMAL_SPI: i_miso is an input, o_mosi is an output
// DUAL_READ: i_miso is an input, o_mosi is an input
// DUAL_WRITE: i_miso is an output, o_mosi is an output
initial o_dspi_mod = NORMAL_SPI;
always @(posedge i_clk)
if (i_reset)
o_dspi_mod <= NORMAL_SPI;
else if (maintenance)