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sign write_flag = (cnt_500hz==TIME_500HZ - 1) ? 1'b1 : 1'b0 ;
//set_function ,display off ，display clear ,entry mode set
//----------------------------------------------------------------------
always @(posedge clk or negedge rst_n)begin
if(rst_n==1'b0)begin
c_state <= IDLE ;
end
else if(write_flag==1) begin
c_state<= n_state ;
end
else
c_state<=c_state ;
end
//-------------------------修改2 因为自定义一个汉字需要写8次地址并且给8次数据，所以用num和num1来控制。
reg [2:0]num,num1;
always @(posedge clk or negedge rst_n)begin
if(rst_n==1'b0)begin
num<=0;
end
else if(c_state== CGRAM_ADDR&&write_flag) begin
if(num==7)
num<=0;
else
num<=num+8'b1;
end
else
num<=num;
end
always @(posedge clk or negedge rst_n)begin
if(rst_n==1'b0)begin
num1<=0;
end
else if(c_state== CGRAM_DATA&&write_flag) begin
if(num1==7)
num1<=0;
else
num1<=num1+8'b1;
end
else
num1<=num1;
end
//------------------------------------------------------------
always @(*)begin
case (c_state)
IDLE: n_state = SET_FUNCTION ;
SET_FUNCTION: n_state = DISP_OFF ;
DISP_OFF: n_state = DISP_CLEAR ;
DISP_CLEAR: n_state = ENTRY_MODE ;
ENTRY_MODE: n_state = DISP_ON ;
DISP_ON : n_state = CGRAM_ADDR ;
//------------------------------------------------ 修改3 当8个数据都写进相应地址里的时候，状态机才跳到ROW1_ADDR状态
CGRAM_ADDR: n_state = CGRAM_DATA ; // 8'hfe;
CGRAM_DATA: if(num1==7)
n_state = ROW1_ADDR;
else
n_state= CGRAM_ADDR;
//------------------------------------------------
ROW1_ADDR: n_state = ROW1_0 ;
ROW1_0: n_state = ROW1_1 ;
ROW1_1: n_state = ROW1_2 ;
ROW1_2: n_state = ROW1_3 ;
ROW1_3: n_state = ROW1_4 ;
ROW1_4: n_state = ROW1_5 ;
ROW1_5: n_state = ROW1_6 ;
ROW1_6: n_state = ROW1_7 ;
ROW1_7: n_state = ROW1_8 ;
ROW1_8: n_state = ROW1_9 ;
ROW1_9: n_state = ROW1_A ;
ROW1_A: n_state = ROW1_B ;
ROW1_B: n_state = ROW1_C ;
ROW1_C: n_state = ROW1_D ;
ROW1_D: n_state = ROW1_E ;
ROW1_E: n_state = ROW1_F ;
ROW1_F: n_state = ROW2_ADDR ;
ROW2_ADDR: n_state = ROW2_0 ;
ROW2_0: n_state = ROW2_1 ;
ROW2_1: n_state = ROW2_2 ;
ROW2_2: n_state = ROW2_3 ;
ROW2_3: n_state = ROW2_4 ;
ROW2_4: n_state = ROW2_5 ;
ROW2_5: n_state = ROW2_6 ;
ROW2_6: n_state = ROW2_7 ;
ROW2_7: n_state = ROW2_8 ;
ROW2_8: n_state = ROW2_9 ;
ROW2_9: n_state = ROW2_A ;
ROW2_A: n_state = ROW2_B ;
ROW2_B: n_state = ROW2_C ;
ROW2_C: n_state = ROW2_D ;
ROW2_D: n_state = ROW2_E ;
ROW2_E: n_state = ROW2_F ;
ROW2_F: n_state = ROW1_ADDR ;
default: n_state = n_state ;
endcase
end
assign lcd_rw = 0;
always @(posedge clk or negedge rst_n)begin
if(rst_n==1'b0)begin
lcd_rs <= 0 ; //order or data 0: order 1:data
end
else if(write_flag == 1)begin
if((n_state==SET_FUNCTION)||(n_state==DISP_OFF)||
(n_state==DISP_CLEAR)||(n_state==ENTRY_MODE)||
(n_state==DISP_ON ) ||(n_state==ROW1_ADDR)||
(n_state==ROW2_ADDR)||(n_state==CGRAM_ADDR))begin //修改4
lcd_rs<=0 ;
end
else begin
lcd_rs<= 1;
end
end
else begin
lcd_rs<=lcd_rs;
end
end
always @(posedge clk or negedge rst_n)begin
if(rst_n==1'b0)begin
lcd_data<=0 ;
end
else if(write_flag)begin
case(n_state)
IDLE: lcd_data <= 8'hxx;
SET_FUNCTION: lcd_data <= 8'h38; //2*16 5*8 8位数据
DISP_OFF: lcd_data <= 8'h08;
DISP_CLEAR: lcd_data <= 8'h01;
ENT |