|
|
@ -19,7 +19,8 @@ parameter IDLE = 4'd0,
|
|
|
|
DEVICE_ADDR = 4'd6,
|
|
|
|
DEVICE_ADDR = 4'd6,
|
|
|
|
DATA = 4'd7,
|
|
|
|
DATA = 4'd7,
|
|
|
|
WAIT = 4'd8,
|
|
|
|
WAIT = 4'd8,
|
|
|
|
STOP = 4'd9;
|
|
|
|
NACK = 4'd9,
|
|
|
|
|
|
|
|
STOP = 4'd10;
|
|
|
|
reg [3: 0] state_c;
|
|
|
|
reg [3: 0] state_c;
|
|
|
|
reg [3: 0] state_n;
|
|
|
|
reg [3: 0] state_n;
|
|
|
|
////
|
|
|
|
////
|
|
|
@ -34,6 +35,7 @@ reg [9: 0] cnt_wait ;//1000us
|
|
|
|
reg skip_en_1 ;//步骤1跳转信号
|
|
|
|
reg skip_en_1 ;//步骤1跳转信号
|
|
|
|
reg skip_en_2 ;//步骤2跳转信号
|
|
|
|
reg skip_en_2 ;//步骤2跳转信号
|
|
|
|
reg skip_en_3 ;//步骤3跳转信号
|
|
|
|
reg skip_en_3 ;//步骤3跳转信号
|
|
|
|
|
|
|
|
reg skip_en_4 ;//步骤4跳转信号
|
|
|
|
reg [2: 0] step ;//步骤
|
|
|
|
reg [2: 0] step ;//步骤
|
|
|
|
reg [1: 0] cnt_i2c_clk ;//i2c计数器
|
|
|
|
reg [1: 0] cnt_i2c_clk ;//i2c计数器
|
|
|
|
reg [2: 0] cnt_bit ;//bit计数器
|
|
|
|
reg [2: 0] cnt_bit ;//bit计数器
|
|
|
@ -45,9 +47,11 @@ reg i2c_scl ;
|
|
|
|
reg [7: 0] slave_addr ;
|
|
|
|
reg [7: 0] slave_addr ;
|
|
|
|
reg [7: 0] device_addr ;
|
|
|
|
reg [7: 0] device_addr ;
|
|
|
|
reg [7: 0] wr_data ;
|
|
|
|
reg [7: 0] wr_data ;
|
|
|
|
|
|
|
|
reg [7: 0] recv_data ;//接受0x20寄存器
|
|
|
|
reg ack ;//接受信号
|
|
|
|
reg ack ;//接受信号
|
|
|
|
|
|
|
|
reg err_en ;//接受到0x20有误
|
|
|
|
//三态门
|
|
|
|
//三态门
|
|
|
|
assign sda_en = ((state_c == ACK_1) || (state_c == ACK_2) || (state_c == ACK_3)) ? 1'b0: 1'b1;//发送主机控制从机,接受主机释放
|
|
|
|
assign sda_en = ((state_c == ACK_1) || (state_c == ACK_2) || (state_c == ACK_3) || (state_c == DATA && step == 3'd3)) ? 1'b0: 1'b1;//发送主机控制从机,接受主机释放
|
|
|
|
assign sda_in = sda;
|
|
|
|
assign sda_in = sda;
|
|
|
|
assign sda = (sda_en == 1'b1)? i2c_sda : 1'bz;
|
|
|
|
assign sda = (sda_en == 1'b1)? i2c_sda : 1'bz;
|
|
|
|
//i2c驱动时钟设计
|
|
|
|
//i2c驱动时钟设计
|
|
|
@ -87,13 +91,13 @@ end
|
|
|
|
//状态机第二段
|
|
|
|
//状态机第二段
|
|
|
|
always @(*)begin
|
|
|
|
always @(*)begin
|
|
|
|
case(state_c)
|
|
|
|
case(state_c)
|
|
|
|
IDLE: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
IDLE: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1) || (skip_en_4 == 1'b1))begin
|
|
|
|
state_n = START;
|
|
|
|
state_n = START;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
state_n = IDLE;
|
|
|
|
state_n = IDLE;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
START: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
START: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1) || (skip_en_4 == 1'b1))begin
|
|
|
|
state_n = SLAVE_ADDR;
|
|
|
|
state_n = SLAVE_ADDR;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
@ -102,7 +106,7 @@ always @(*)begin
|
|
|
|
SLAVE_ADDR: if(skip_en_1 == 1'b1)begin
|
|
|
|
SLAVE_ADDR: if(skip_en_1 == 1'b1)begin
|
|
|
|
state_n = WAIT;
|
|
|
|
state_n = WAIT;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
else if((skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
else if((skip_en_2 == 1'b1) || (skip_en_3 == 1'b1) || (skip_en_4 == 1'b1))begin
|
|
|
|
state_n = ACK_1;
|
|
|
|
state_n = ACK_1;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
@ -111,6 +115,9 @@ always @(*)begin
|
|
|
|
ACK_1: if((skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
ACK_1: if((skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
state_n = DEVICE_ADDR;
|
|
|
|
state_n = DEVICE_ADDR;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
else if(skip_en_4 == 1'b1)begin
|
|
|
|
|
|
|
|
state_n = DATA;
|
|
|
|
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
state_n = ACK_1;
|
|
|
|
state_n = ACK_1;
|
|
|
|
end
|
|
|
|
end
|
|
|
@ -132,9 +139,21 @@ always @(*)begin
|
|
|
|
DATA: if(skip_en_2 == 1'b1)begin
|
|
|
|
DATA: if(skip_en_2 == 1'b1)begin
|
|
|
|
state_n = ACK_3;
|
|
|
|
state_n = ACK_3;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
else if(skip_en_4 == 1'b1)begin
|
|
|
|
|
|
|
|
state_n = NACK;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else if(err_en == 1'b1)begin
|
|
|
|
|
|
|
|
state_n = IDLE;
|
|
|
|
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
state_n = DATA;
|
|
|
|
state_n = DATA;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
NACK: if(skip_en_4 == 1'b1)begin
|
|
|
|
|
|
|
|
state_n = STOP;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
state_n = NACK;
|
|
|
|
|
|
|
|
end
|
|
|
|
ACK_3: if(skip_en_2 == 1'b1)begin
|
|
|
|
ACK_3: if(skip_en_2 == 1'b1)begin
|
|
|
|
state_n = STOP;
|
|
|
|
state_n = STOP;
|
|
|
|
end
|
|
|
|
end
|
|
|
@ -147,7 +166,7 @@ always @(*)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
state_n = WAIT;
|
|
|
|
state_n = WAIT;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
STOP: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1))begin
|
|
|
|
STOP: if((skip_en_1 == 1'b1) || (skip_en_2 == 1'b1) || (skip_en_3 == 1'b1) || (skip_en_4 == 1'b1))begin
|
|
|
|
state_n = IDLE;
|
|
|
|
state_n = IDLE;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
@ -165,7 +184,9 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
skip_en_1 <= 1'b0;//步骤1跳转信号
|
|
|
|
skip_en_1 <= 1'b0;//步骤1跳转信号
|
|
|
|
skip_en_2 <= 1'b0;//步骤2跳转信号
|
|
|
|
skip_en_2 <= 1'b0;//步骤2跳转信号
|
|
|
|
skip_en_3 <= 1'b0;//步骤3跳转信号
|
|
|
|
skip_en_3 <= 1'b0;//步骤3跳转信号
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;//步骤4跳转信号
|
|
|
|
step <= 3'd0;
|
|
|
|
step <= 3'd0;
|
|
|
|
|
|
|
|
err_en <= 1'b0;
|
|
|
|
cnt_i2c_clk <= 2'd0;
|
|
|
|
cnt_i2c_clk <= 2'd0;
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
|
i2c_end <= 1'b0;
|
|
|
|
i2c_end <= 1'b0;
|
|
|
@ -197,6 +218,12 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_wait == MAX - 2'd2) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
START: begin
|
|
|
|
START: begin
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'd1;
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'd1;
|
|
|
@ -218,6 +245,12 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd2) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
SLAVE_ADDR: begin
|
|
|
|
SLAVE_ADDR: begin
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'd1;
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'd1;
|
|
|
@ -239,6 +272,12 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd2) && (step == 3'd3) && (cnt_bit == 3'd7))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
if((cnt_bit == 3'd7) && (cnt_i2c_clk == 2'd3))begin
|
|
|
|
if((cnt_bit == 3'd7) && (cnt_i2c_clk == 2'd3))begin
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
|
end
|
|
|
|
end
|
|
|
@ -263,6 +302,12 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((ack == 1'b1) && (cnt_i2c_clk == 2'd2) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
DEVICE_ADDR:begin
|
|
|
|
DEVICE_ADDR:begin
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'b1;
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1'b1;
|
|
|
@ -320,6 +365,33 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_2 <= 1'b0;
|
|
|
|
skip_en_2 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd2) && (cnt_bit == 3'd7) && (step == 3'd3) && (recv_data == 8'h20))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd2) && (cnt_bit == 3'd7) && (step == 3'd3) && (recv_data != 8'h20))begin
|
|
|
|
|
|
|
|
begin
|
|
|
|
|
|
|
|
err_en <= 1'b1;
|
|
|
|
|
|
|
|
step <= 3'd0;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
begin
|
|
|
|
|
|
|
|
err_en <= 1'b0;
|
|
|
|
|
|
|
|
step <= step;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
NACK: begin
|
|
|
|
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1;
|
|
|
|
|
|
|
|
if((ack == 1'b1) && (cnt_i2c_clk == 2'd2) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
ACK_3: begin
|
|
|
|
ACK_3: begin
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1;
|
|
|
|
cnt_i2c_clk <= cnt_i2c_clk + 1;
|
|
|
@ -364,6 +436,12 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
else begin
|
|
|
|
else begin
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd2) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b1;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
end
|
|
|
|
if(cnt_i2c_clk == 2'd2)begin
|
|
|
|
if(cnt_i2c_clk == 2'd2)begin
|
|
|
|
i2c_end <= 1'b1;
|
|
|
|
i2c_end <= 1'b1;
|
|
|
|
end
|
|
|
|
end
|
|
|
@ -382,6 +460,8 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
skip_en_1 <= 1'b0;
|
|
|
|
skip_en_1 <= 1'b0;
|
|
|
|
skip_en_2 <= 1'b0;
|
|
|
|
skip_en_2 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
skip_en_3 <= 1'b0;
|
|
|
|
|
|
|
|
skip_en_4 <= 1'b0;
|
|
|
|
|
|
|
|
err_en <= 1'b0;
|
|
|
|
step <= step;
|
|
|
|
step <= step;
|
|
|
|
cnt_i2c_clk <= 2'd0;
|
|
|
|
cnt_i2c_clk <= 2'd0;
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
|
cnt_bit <= 3'd0;
|
|
|
@ -390,10 +470,30 @@ always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
endcase
|
|
|
|
endcase
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
end
|
|
|
|
|
|
|
|
//recv_data
|
|
|
|
|
|
|
|
always @(posedge i2c_clk or negedge sys_rst_n)begin
|
|
|
|
|
|
|
|
if(!sys_rst_n)begin
|
|
|
|
|
|
|
|
recv_data <= 8'h0;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
case(state_c)
|
|
|
|
|
|
|
|
DATA: begin
|
|
|
|
|
|
|
|
if((cnt_i2c_clk == 2'd1) && (step == 3'd3))begin
|
|
|
|
|
|
|
|
recv_data <= {recv_data[6:0], sda_in};
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
recv_data <= recv_data;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
default: recv_data <= recv_data;
|
|
|
|
|
|
|
|
endcase
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
end
|
|
|
|
//ack
|
|
|
|
//ack
|
|
|
|
always @(*)begin
|
|
|
|
always @(*)begin
|
|
|
|
case(state_c)
|
|
|
|
case(state_c)
|
|
|
|
ACK_1, ACK_2, ACK_3: ack = ~sda_in;
|
|
|
|
ACK_1, ACK_2, ACK_3: ack = ~sda_in;
|
|
|
|
|
|
|
|
NACK: ack = i2c_sda;//主机发送NACK
|
|
|
|
default: ack = 1'b0;
|
|
|
|
default: ack = 1'b0;
|
|
|
|
endcase
|
|
|
|
endcase
|
|
|
|
end
|
|
|
|
end
|
|
|
@ -412,7 +512,12 @@ always @(*)begin
|
|
|
|
end
|
|
|
|
end
|
|
|
|
3'd2: begin
|
|
|
|
3'd2: begin
|
|
|
|
slave_addr = {SLAVE_ID, 1'b0};
|
|
|
|
slave_addr = {SLAVE_ID, 1'b0};
|
|
|
|
device_addr= {8'hef};
|
|
|
|
device_addr= {8'h00};
|
|
|
|
|
|
|
|
wr_data = {8'h00};
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
3'd3: begin
|
|
|
|
|
|
|
|
slave_addr = {SLAVE_ID, 1'b1};//读取
|
|
|
|
|
|
|
|
device_addr= {8'h00};
|
|
|
|
wr_data = {8'h00};
|
|
|
|
wr_data = {8'h00};
|
|
|
|
end
|
|
|
|
end
|
|
|
|
default:begin
|
|
|
|
default:begin
|
|
|
@ -427,7 +532,7 @@ always @(*)begin
|
|
|
|
case(state_c)
|
|
|
|
case(state_c)
|
|
|
|
IDLE: i2c_scl = 1'b1;
|
|
|
|
IDLE: i2c_scl = 1'b1;
|
|
|
|
START: i2c_scl = (cnt_i2c_clk <= 2'd2) ? 1'b1 : 1'b0;
|
|
|
|
START: i2c_scl = (cnt_i2c_clk <= 2'd2) ? 1'b1 : 1'b0;
|
|
|
|
SLAVE_ADDR, DEVICE_ADDR, DATA, ACK_1, ACK_2, ACK_3:
|
|
|
|
SLAVE_ADDR, DEVICE_ADDR, DATA, ACK_1, ACK_2, ACK_3, NACK:
|
|
|
|
i2c_scl = ((cnt_i2c_clk == 2'd1) || (cnt_i2c_clk == 2'd2)) ? 1'b1 : 1'b0;
|
|
|
|
i2c_scl = ((cnt_i2c_clk == 2'd1) || (cnt_i2c_clk == 2'd2)) ? 1'b1 : 1'b0;
|
|
|
|
WAIT: i2c_scl = 1'b0;
|
|
|
|
WAIT: i2c_scl = 1'b0;
|
|
|
|
STOP: i2c_scl = (cnt_i2c_clk >= 2'd1) ? 1'b1 : 1'b0;
|
|
|
|
STOP: i2c_scl = (cnt_i2c_clk >= 2'd1) ? 1'b1 : 1'b0;
|
|
|
@ -440,10 +545,16 @@ always @(*)begin
|
|
|
|
START: i2c_sda = (cnt_i2c_clk > 2'd1) ? 1'b0 : 1'b1;
|
|
|
|
START: i2c_sda = (cnt_i2c_clk > 2'd1) ? 1'b0 : 1'b1;
|
|
|
|
SLAVE_ADDR: i2c_sda = slave_addr[7 - cnt_bit];
|
|
|
|
SLAVE_ADDR: i2c_sda = slave_addr[7 - cnt_bit];
|
|
|
|
DEVICE_ADDR:i2c_sda = device_addr[7 - cnt_bit];
|
|
|
|
DEVICE_ADDR:i2c_sda = device_addr[7 - cnt_bit];
|
|
|
|
DATA: i2c_sda = wr_data[7 - cnt_bit];
|
|
|
|
DATA: if(step == 3'd3)begin
|
|
|
|
|
|
|
|
i2c_sda = sda_in;
|
|
|
|
|
|
|
|
end
|
|
|
|
|
|
|
|
else begin
|
|
|
|
|
|
|
|
i2c_sda = wr_data[7 - cnt_bit];
|
|
|
|
|
|
|
|
end
|
|
|
|
ACK_1, ACK_2, ACK_3:
|
|
|
|
ACK_1, ACK_2, ACK_3:
|
|
|
|
i2c_sda = 1'b0;
|
|
|
|
i2c_sda = 1'b0;
|
|
|
|
WAIT: i2c_sda = 1'b0;
|
|
|
|
WAIT: i2c_sda = 1'b0;
|
|
|
|
|
|
|
|
NACK: i2c_sda = 1'b1;//主机给从机发1
|
|
|
|
STOP: i2c_sda = (cnt_i2c_clk >= 2'd2) ? 1'b1 : 1'b0;
|
|
|
|
STOP: i2c_sda = (cnt_i2c_clk >= 2'd2) ? 1'b1 : 1'b0;
|
|
|
|
default: i2c_sda = 1'b1;
|
|
|
|
default: i2c_sda = 1'b1;
|
|
|
|
endcase
|
|
|
|
endcase
|
|
|
|