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Commit 2a260f5a authored by Andrey Filippov's avatar Andrey Filippov
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continue on sensor i2c

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sensor/sensor_i2c_prot.v
View file @ 2a260f5a
......@@ -21,65 +21,205 @@
`timescale 1ns/1ps
module sensor_i2c_prot(
input mrst, // @ posedge mclk
input mclk, // global clock
input i2c_rst,
input i2c_start,
input [ 7:0] i2c_dly, // bit duration-1 (>=2?), 1 unit - 4 mclk periods
input mrst, // @ posedge mclk
input mclk, // global clock
input i2c_rst,
input i2c_start,
input [ 7:0] i2c_dly, // bit duration-1 (>=2?), 1 unit - 4 mclk periods
// setup LUT to translate address page into SA, actual address MSB and number of bytes to write (second word bypasses translation)
input tand, // table address/not data
input [19:0] td, // table address/data in
input twe, // table write enable
output reg sda,
output reg sda_en,
output reg scl,
output i2c_run,
output [ 1:0] seq_mem_ra, // number of byte to read from the sequencer memory
output [ 1:0] seq_mem_re, // [0] - re, [1] - regen to teh sequencer memory
input [ 7:0] seq_rd, // data from the sequencer memory
output [ 7:0] rdata,
output rvalid
input tand, // table address/not data
input [19:0] td, // table address/data in
input twe, // table write enable
input sda_in, // data from sda pad
output reg sda,
output reg sda_en,
output reg scl,
output i2c_run,
output reg [1:0] seq_mem_ra, // number of byte to read from the sequencer memory
output [ 1:0] seq_mem_re, // [0] - re, [1] - regen to teh sequencer memory
input [ 7:0] seq_rd, // data from the sequencer memory
output [ 7:0] rdata,
output rvalid
);
reg [ 7:0] twa;
wire [31:0] tdout;
wire [ 7:0] reg_ah = tdout[7:0]; // MSB of the register address (instead of the byte 2)
wire [ 6:0] slave_a = tdout[14:8]; // 7-bit slave address (lsb == 1), used instead of the byte 3
wire [ 3:0] num_bytes_send = tdout[19:16]; // number of bytes to send (if more than 4 will skip stop and continue with next data
reg [ 7:0] reg_ah; // MSB of the register address (instead of the byte 2)
reg [ 7:0] slave_a_rah; // 8-bit slave address , used instead of the byte 3, later replaced with reg_ah
reg [ 3:0] num_bytes_send; // number of bytes to send (if more than 4 will skip stop and continue with next data
reg [ 3:0] bytes_left_send; // Number of bytes left in register write sequence (not counting sa?)
reg run_reg_wr; // run register write
reg run_extra_wr; // continue register write (if more than sa + 4bytes)
reg run_reg_rd;
reg [ 6:0] run_reg_wr; // run register write [6] - start, [5] - send sa, [4] - send high byte (from table),..[0] - send stop
reg [ 4:0] run_extra_wr; // continue register write (if more than sa + 4bytes) [4] - byte 3, .. [1]- byte0, [0] - stop
reg run_extra_wr_d; // any of run_extra_wr bits, delayed by 1
reg [ 7:0] run_reg_rd; // [7] - start, [6] SA (byte 3), [5] (optional) - RA_msb, [4] - RA_lsb, [3] - restart, [2] - SA, [1] - read bytes, [0] - stop
reg i2c_done;
wire i2c_next_byte;
reg [ 2:0] mem_re;
reg [ 2:0] table_re;
reg mem_valid;
reg [ 3:0] table_re;
reg read_mem_msb;
wire decode_reg_rd = &seq_rd[7:4];
wire start_wr_seq_w = !run_extra_wr_d && !decode_reg_rd && read_mem_msb;
wire decode_reg_rd = &seq_rd[7:5];
wire start_wr_seq = !run_extra_wr && !decode_reg_rd && read_mem_msb;
reg read_mem_msb;
wire snd_start_w = run_reg_wr[6] || 1'b0; // add start & restart of read
wire snd_stop_w = run_reg_wr[0] || 1'b0; // add stop of read
wire snd9_w = (|run_reg_wr[5:1]) || 1'b0; // add for read and extra write;
reg snd_start;
reg snd_stop;
reg snd9;
// the following signals are mutually exclusive, can be encoded to 2 bits. Invaluid during next_cmd_d
reg send_seq_data; // including first SA for read
reg send_rd_sa; // from the table
reg send_sa_rah; // send slave address/ high address from the table
reg send_rd; // send 1fe/1ff to read data
reg [6:0] rd_sa; // 7-bit slave address for reading
wire [1:0] sel_sr_in = { // select source for the shift register
send_sa_rah | send_rd,
send_rd_sa | send_rd};
reg [8:0] sr_in; // input data for the shift register
wire i2c_rdy;
reg next_cmd; // i2c command (start/stop/data) accepted, proceed to the next stage
reg next_cmd_d; // next cycle after next_cmd (first at new state)
wire pre_next_cmd = (snd_start || snd_stop || snd9) && i2c_rdy;
reg next_byte_wr;
reg read_address_bytes; // 0 - single-byte register adderss, 1 - two-byte register address
reg [ 2:0] read_data_bytes; // 1..8 bytes to read from teh i2c slave (0 is 8!)
reg [ 1:0] initial_address; // initial data byte to read: usually 3 but for extra write may be different
wire [ 3:0] initial_address_w = bytes_left_send - 1; // if bytes left to send == 0 - will be 3
wire unused; // unused ackn signal
assign seq_mem_re = mem_re[1:0];
always @ (posedge mclk) begin
read_mem_msb <= mem_re[1] && (seq_mem_ra == 3); // reading sequencer data MSB
mem_re <= {mem_re[1:0], i2c_start | i2c_next_byte};
table_re <= {table_re[1:0], start_wr_seq};
run_extra_wr_d <= |run_extra_wr;
read_mem_msb <= mem_re[1] && (seq_mem_ra == 3); // reading sequencer data MSB - change to other one-hot?
table_re <= {table_re[2:0], start_wr_seq_w};
if (table_re[2]) begin
reg_ah <= tdout[7:0]; // MSB of the register address (instead of the byte 2)
num_bytes_send <= tdout[19:16]; // number of bytes to send (if more than 4 will skip stop and continue with next data
end
if (table_re[2]) slave_a_rah <= {tdout[14:8], 1'b0};
else if (next_cmd && run_reg_wr[6]) slave_a_rah <= reg_ah; // will copy even if not used
next_cmd <= pre_next_cmd;
next_cmd_d <= next_cmd;
if (mrst || i2c_rst) run_extra_wr <= 0;
else if (i2c_start && (bytes_left_send !=0)) run_extra_wr <= 1;
else if (i2c_done) run_extra_wr <= 0;
next_byte_wr <= snd9 && i2c_rdy; // same time as next_cmd
if (mrst || i2c_rst) run_reg_wr <= 0;
else if (start_wr_seq) run_reg_wr <= 1;
else if (i2c_done) run_reg_wr <= 0;
snd_start <= snd_start_w; // add & i2c_ready? Not really needed as any i2c stage will be busy for long enough
snd_stop <= snd_stop_w;
snd9 <= snd9_w;
if (mrst || i2c_rst) bytes_left_send <= 0;
else if (start_wr_seq_w) bytes_left_send <= num_bytes_send;
else if (next_byte_wr) bytes_left_send <= bytes_left_send - 1;
// calculate stages for each type of commands
// start and write sa and some bytes, stop if number of bytes <= 4 at teh end
if (mrst || i2c_rst) run_reg_wr <= 0;
else if (start_wr_seq_w) run_reg_wr <= 7'h40;
else if (next_cmd) run_reg_wr <= {1'b0, // first "start"
run_reg_wr[6], // slave_addr - always after start
run_reg_wr[5] & (|num_bytes_send[3:2]), // MSB (from the table)
run_reg_wr[4] | (run_reg_wr[5] & (num_bytes_send == 4'h3)), // byte 2 (from input)
run_reg_wr[3] | (run_reg_wr[5] & (num_bytes_send == 4'h2)), // byte 1 (from input)
run_reg_wr[2] | (run_reg_wr[5] & (num_bytes_send == 4'h1)), // byte 0 (from input)
run_reg_wr[1] & (bytes_left_send == 4'h1)
};
// send just bytes (up to 4), stop if nothing left
if (mrst || i2c_rst) run_extra_wr <= 0;
else if (i2c_start && (bytes_left_send !=0)) run_extra_wr <= {
|bytes_left_send[3:2], // >= 4 bytes left
(bytes_left_send == 3), // exactly 3 bytes left
(bytes_left_send == 2), // exactly 2 bytes left
(bytes_left_send == 1), // exactly 1 bytes left (zero should never be left)
1'b0
};
else if (next_cmd) run_extra_wr <= {
1'b0,
run_extra_wr[4],
run_extra_wr[3],
run_extra_wr[2],
run_extra_wr[1] & (bytes_left_send == 4'h1)
};
// reg [ 7:0] run_reg_rd; // [7] - start, [6] SA (byte 3), [5] (optional) - RA_msb, [4] - RA_lsb, [3] - restart, [2] - SA, [1] - read bytes, [0] - stop
if (mrst || i2c_rst) run_reg_rd <= 0;
else if (!run_extra_wr && decode_reg_rd && read_mem_msb) run_reg_rd <= 1;
else if (i2c_done) run_reg_rd <= 0;
if (!run_extra_wr && decode_reg_rd && read_mem_msb) read_address_bytes <= seq_rd[3];
if (!run_extra_wr && decode_reg_rd && read_mem_msb) read_data_bytes <= seq_rd[2:0];
else if (run_reg_rd[1] && next_cmd) read_data_bytes <= read_data_bytes - 1;
// read i2c data
if (mrst || i2c_rst) run_reg_rd <= 0;
else if (!run_extra_wr_d && decode_reg_rd && read_mem_msb) run_reg_rd <= 8'h80;
else if (next_cmd) run_reg_rd <= {1'b0, // first "start"
run_reg_rd[7], // slave_addr - always after start (bit0 = 0)
run_reg_rd[6] & read_address_bytes, // optional MSB of the register address
run_reg_rd[5] | (run_reg_rd[6] & ~read_address_bytes), // LSB of the register address
run_reg_rd[4], // restart
run_reg_rd[3], // send slave address with 1 in bit[0]
run_reg_rd[2] | (run_reg_rd[1] & (read_data_bytes != 3'h1)), // repeat reading bytes
run_reg_rd[1] & (read_data_bytes == 3'h1)
};
// read sequencer memory byte (for the current word)
mem_re <= {mem_re[1:0], i2c_start | next_cmd_d & (
(|run_reg_wr[3:1]) |
(|run_extra_wr[4:1]) |
(|run_reg_rd[6:4]))};
initial_address <= initial_address_w[1:0]; // if bytes left to send is 0 mod 4 - will be 3 (read MSB)
seq_mem_ra <= i2c_start ? initial_address : { // run_extra_wr[4] is not needed - it will be read by i2c_start
run_reg_wr[3] | run_extra_wr[3] | run_reg_rd[6],
run_reg_wr[2] | run_extra_wr[2] | run_reg_rd[5]
};
if (mrst || i2c_rst || i2c_start || next_cmd ) mem_valid <= 0;
else if (mem_re[2]) mem_valid <= 1;
// calculate snd9 and delay it if waiting for memory using mem_valid, set din[8:0]
if (run_reg_rd[6] && mem_re[2]) rd_sa <= seq_rd[7:1]; // store sa to use with read
send_seq_data <= !next_cmd && mem_valid && ((|run_reg_wr[3:1]) || (|run_extra_wr[4:1]) || (|run_reg_rd[6:4]));
send_rd_sa <= !next_cmd && run_reg_rd[2];
send_sa_rah <= !next_cmd && (|run_reg_wr[6:5]);
send_rd <= !next_cmd && run_reg_rd[1];
if (mrst || i2c_rst) snd9 <= 0;
else snd9 <= snd9 ? (!i2c_rdy) : ((send_seq_data || send_rd_sa || send_sa_rah || send_rd) && !next_cmd);
case (sel_sr_in)
2'h0: sr_in <= {seq_rd, 1'b1};
2'h1: sr_in <= {rd_sa, 2'b11};
2'h2: sr_in <= {slave_a_rah, 1'b1};
2'h3: sr_in <= {8'hff,(read_data_bytes == 3'h1)};
endcase
// table_re[2] - valid table data (slave_a, reg_ah, reg_ah
end
sensor_i2c_scl_sda sensor_i2c_scl_sda_i (
.mrst (mrst), // input
.mclk (mclk), // input
.i2c_rst (i2c_rst), // input
.i2c_dly (i2c_dly), // input[7:0]
.snd_start (snd_start), // input
.snd_stop (snd_stop), // input
.snd9 (snd9), // input
.din (sr_in), // input[8:0]
.dout ({rdata,unused}),// output[8:0]
.dout_stb (rvalid), // output reg
.scl (), // output reg
.sda_in (sda_in), // input
.sda (), // output reg
.ready (i2c_rdy), // output register
.bus_busy (), // output reg
.is_open () // output
);
// table write
......
sensor/sensor_i2c_scl_sda.v 0 → 100644
View file @ 2a260f5a
/*******************************************************************************
* Module: sensor_i2c_scl_sda
* Date:2015-10-06
* Author: andrey
* Description: Generation of i2c signals
*
* Copyright (c) 2015 Elphel, Inc .
* sensor_i2c_scl_sda.v is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* sensor_i2c_scl_sda.v 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/> .
*******************************************************************************/
`timescale 1ns/1ps
module sensor_i2c_scl_sda(
input mrst, // @ posedge mclk
input mclk, // global clock
input i2c_rst,
input [ 7:0] i2c_dly, // bit duration-1 (>=2?), 1 unit - 4 mclk periods
input snd_start,
input snd_stop,
input snd9,
input [ 8:0] din,
output [ 8:0] dout, //
output reg dout_stb, // dout contains valid data
output reg scl, // i2c SCL signal
input sda_in, // i2c SDA signal form I/O pad
output reg sda, // i2c SDA signal
output ready, // ready to accept commands
output reg bus_busy, // i2c bus busy (1 cycle behind !ready)
output is_open // i2c channel is open (started, no stop yet)
);
wire rst = mrst || i2c_rst;
reg is_open_r;
reg [8:0] sr;
reg [7:0] dly_cntr;
reg busy_r;
wire snd_start_w = snd_start && !busy_r;
wire snd_stop_w = snd_stop && !busy_r;
wire snd9_w = snd9 && !busy_r;
wire start_w = (snd_start || snd_stop || snd9_w) && !busy_r;
reg pre_dly_over;
reg dly_over;
reg [3:0] seq_start_restart;
reg [2:0] seq_stop;
reg [3:0] seq_bit;
reg [3:0] bits_left;
reg done_r;
reg sda_r;
reg first_cyc; // first clock cycle for the delay interval - update SCL/SDA outputs
assign ready = !busy_r;
assign is_open = is_open_r;
assign dout = sr;
always @ (posedge mclk) begin
if (rst) seq_start_restart <= 0;
else if (snd_start_w) seq_start_restart <= is_open_r ? 4'h8 : 4'h4;
else if (dly_over) seq_start_restart <= {1'b0,seq_start_restart[3:1]};
if (rst) seq_stop <= 0;
else if (snd_stop_w) seq_stop <= 3'h4;
else if (dly_over) seq_stop <= {1'b0,seq_stop[2:1]};
if (rst) seq_bit <= 0;
else if (snd_start_w || (seq_bit[0] && (bits_left != 0))) seq_bit <= 4'h8;
else if (dly_over) seq_bit <= {1'b0,seq_bit[3:1]};
if (rst) bits_left <= 0;
else if (snd9_w) bits_left <= 4'h8;
else if (dly_over && seq_bit[0]) bits_left <= bits_left - 1;
if (rst) busy_r <= 0;
else if (start_w) busy_r <= 1;
else if (done_r) busy_r <= 0;
pre_dly_over <= (dly_cntr == 2);
dly_over <= pre_dly_over;
if (rst) done_r <= 0;
else done_r <= pre_dly_over &&
(bits_left == 0) &&
(seq_start_restart[3:1] == 0) &&
(seq_stop[2:1] == 0) &&
(bits_left[3:1] == 0);
if (!busy_r || dly_over) dly_cntr <= i2c_dly;
else dly_cntr <= dly_cntr - 1;
if (dly_over && seq_bit[1]) sda_r <= sda_in; // just before the end of SCL pulse - delay it by a few clocks to match external latencies?
if (snd_start_w) sr <= din;
else if (dly_over && seq_bit[0]) sr <= {sr[7:0], sda_r};
dout_stb <= dly_over && seq_bit[0] && (bits_left == 0);
if (rst) is_open_r <= 0;
else if (dly_over && seq_start_restart[0]) is_open_r <= 1;
else if (dly_over && seq_stop[0]) is_open_r <= 0;
first_cyc <= start_w || dly_over;
if (rst) scl <= 1;
else if (first_cyc) scl <= !busy_r ||
seq_start_restart[2] || seq_start_restart[1] ||
seq_stop[1] || seq_stop[0] ||
seq_bit[2] || seq_bit[1];
if (rst) sda <= 1;
else if (first_cyc) sda <= !busy_r ||
seq_start_restart[3] || seq_start_restart[2] ||
seq_stop[0] ||
(sr[8] && (|seq_bit));
bus_busy <= busy_r;
end
endmodule
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