MS5611的ZYNQ驱动试验之三 控制器代码实现

1，归纳抽象

我们上述分析归纳了实际上只需要三类操作

1，执行命令操作。包含三个操作 RESET 转换D1 转换D2。

2，读出6个16位校准字。

3，读出D1 D2.

其中第一条是阻塞的，也就是要等SDO为高后才能认为执行完毕并返回。

上述三个操作我们都分别命名为ISSUE_CMD，RD_U16，RD_U24。

2，有限状态机FSM是使用HDL在并行的硬件里面实现类似C语言那样串行执行指令的一种很好方式。

我们考虑在C语言中函数实现的特点：

 A,要有一个函数名，实际对应函数地址。

B,可以有一个输入参数。有一定方式传递这个参数。

C,可以有一个返回结果。有一定的方式传递这个结果。

D，无论是否有输入参数和返回结果，必须要做一些事情。

E，要有返回地址。

3，上述C函数的实现方式是最基本的我们考虑在HDL写的FSM里面如何实现。

直接上代码：

ISSUE_CMD + 0  : begin  CSN<=0; SCK<=0;MO<=A[7];st<=st+1;end
ISSUE_CMD + 1  : begin  CSN<=0; SCK<=1;MO<=A[7];st<=st+1;end
ISSUE_CMD + 2  : begin  CSN<=0; SCK<=0;MO<=A[6];st<=st+1;end
ISSUE_CMD + 3  : begin  CSN<=0; SCK<=1;MO<=A[6];st<=st+1;end
ISSUE_CMD + 4  : begin  CSN<=0; SCK<=0;MO<=A[5];st<=st+1;end
ISSUE_CMD + 5  : begin  CSN<=0; SCK<=1;MO<=A[5];st<=st+1;end
ISSUE_CMD + 6  : begin  CSN<=0; SCK<=0;MO<=A[4];st<=st+1;end
ISSUE_CMD + 7  : begin  CSN<=0; SCK<=1;MO<=A[4];st<=st+1;end
ISSUE_CMD + 8  : begin  CSN<=0; SCK<=0;MO<=A[3];st<=st+1;end
ISSUE_CMD + 9  : begin  CSN<=0; SCK<=1;MO<=A[3];st<=st+1;end
ISSUE_CMD + 10 : begin  CSN<=0; SCK<=0;MO<=A[2];st<=st+1;end
ISSUE_CMD + 11 : begin  CSN<=0; SCK<=1;MO<=A[2];st<=st+1;end
ISSUE_CMD + 12 : begin  CSN<=0; SCK<=0;MO<=A[1];st<=st+1;end
ISSUE_CMD + 13 : begin  CSN<=0; SCK<=1;MO<=A[1];st<=st+1;end
ISSUE_CMD + 14 : begin  CSN<=0; SCK<=0;MO<=A[0];st<=st+1;end
ISSUE_CMD + 15 : begin  CSN<=0; SCK<=1;MO<=A[0];st<=st+1;end
ISSUE_CMD + 16 : begin  CSN<=0; SCK<=0;if (MIr)st<=st+1;end
ISSUE_CMD + 17 : st<=st+1;
ISSUE_CMD + 18 : st<=st+1;
ISSUE_CMD + 19 : begin CSN<=1; st<=st+1;end 
ISSUE_CMD + 20 : st<=st+1;
ISSUE_CMD + 21 : st <= RET_ST; 

 

我们暂且说这是FSM实现的ISSUE_CMD函数，下面是调用这个函数的代码：

0: st<=1;
1: begin CSN <=1 ;SCK<=0; st<=10;end 
10: begin A[7:0]<='H1E; RET_ST<=st+1;st<= ISSUE_CMD ;end 
11: st<=st+1; ///reset 

31: begin A[7:0]<=CNVT_D1r; RET_ST<=st+1;st<= ISSUE_CMD ;end 
32: st<=st+1;
33: begin RET_ST<=st+1; st<=RD_U24;end 
34: begin q <= {8'h0,R[23:0]} ;q_valid<=1; st<=st+1 ;end 
35: begin q_valid<=0;  st<=st+1 ;end 

这里我们我们通过寄存器A传递过去要发送的命令，设置RET_ST记录返回地址是当前状态的下一个状态，之后转跳到ISSUE_CMD这个地址依次一条条执行，将A寄存器的7为都传输出去。发出去之后,再转跳回去原来的地址。另外我们看到RD_U24的返回的结果保存在R寄存器里，这就实现了类似函数的返回。

全部的代码我贴在下面：

/*
ms5611_man ms5611_man(
.clk( ) ,
.rst( ) ,
.CSN( ) ,
.SCK( ) ,
.MO( ) ,
.MIr( ) ,
.CNVT_D1( ) ,
.CNVT_D2( ) ,
.Q( ) ,
.Q_WR( )  ,
.start_rd_u24( )   
);
*/

module ms5611_man(
input clk,rst,
output reg CSN,SCK,MO,
input MI,
input [7:0] CNVT_D1,
input [7:0] CNVT_D2,
output reg  [31:0]  Q,
output reg Q_WR ,
input start_rd_u24  
);
reg [15:0]  st  =  0 ;
reg [7:0] A;
reg [15:0]  RET_ST ;
reg [23:0] R;
reg q_valid , q_validr ;
reg  [31:0] q ; 
reg [7:0] CNVT_D2r;
reg [7:0] CNVT_D1r; 
reg MIr ;always@(posedge clk)MIr <= MI ;
always@(posedge clk)if (start_rd_u24==1 &&  st == 30) begin
 CNVT_D2r <= CNVT_D2 ; 
CNVT_D1r  <= CNVT_D1 ;
end 

//parameter CVT_D1 = 'H48 ;
//parameter CVT_D2 = 'H58 ;

localparam 	ISSUE_CMD =  100 ;
localparam 	RD_U16    =  200 ;
localparam	RD_U24    =  300 ; 

always @(posedge clk ) q_validr <= q_valid ;
always @(posedge clk ) Q_WR <= {q_validr,q_valid} == 2'b01 ; 
always @(posedge clk ) Q <= q ; 

reg [8:0] d = 0 ; always @(posedge clk )d<=d+1;
 

always @ (posedge clk) if (rst) st<=0; else if (d==0) 
case (st)
0: st<=1;
1: begin CSN <=1 ;SCK<=0; st<=10;end 
10: begin A[7:0]<='H1E; RET_ST<=st+1;st<= ISSUE_CMD ;end 
11: st<=st+1; ///reset 

12: begin A[7:0] <= 'HA2+'h0 ; RET_ST<=st+1;st<= RD_U16 ;  end 
13: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
14: begin q_valid<=0;  st<=st+1 ;end //read c0

15: begin A[7:0] <= 'HA2+'h2 ; RET_ST<=st+1;st<= RD_U16 ;  end 
16: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
17: begin q_valid<=0;  st<=st+1;end  //read c1

18: begin A[7:0] <= 'HA2+'h4 ; RET_ST<=st+1;st<= RD_U16 ;  end 
19: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
20: begin q_valid<=0;  st<=st+1; end //read c2

21: begin A[7:0] <= 'HA2+'h6 ; RET_ST<=st+1;st<= RD_U16 ;  end 
22: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
23: begin q_valid<=0;  st<=st+1; end //read c3

24: begin A[7:0] <= 'HA2+'h8 ; RET_ST<=st+1;st<= RD_U16 ;  end 
25: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
26: begin q_valid<=0;  st<=st+1; end //read c4

27: begin A[7:0] <= 'HA2+'ha; RET_ST<=st+1;st<= RD_U16 ;  end 
28: begin q <= {8'h0,R[15:0]} ;q_valid<=1; st<=st+1 ;end 
29: begin q_valid<=0;  st<=st+1; end //read c5
  
30: if (start_rd_u24) st<=31;
 
31: begin A[7:0]<=CNVT_D1r; RET_ST<=st+1;st<= ISSUE_CMD ;end 
32: st<=st+1;
33: begin RET_ST<=st+1; st<=RD_U24;end 
34: begin q <= {8'h0,R[23:0]} ;q_valid<=1; st<=st+1 ;end 
35: begin q_valid<=0;  st<=st+1 ;end 

36: begin A[7:0]<=CNVT_D2r; RET_ST<=st+1;st<= ISSUE_CMD ;end 
37: st<=st+1;
38: begin RET_ST<=st+1; st<=RD_U24;end 
39: begin q <= {8'h0,R[23:0]} ;q_valid<=1; st<=st+1 ;end 
40: begin q_valid<=0;  st<=st+1 ;end 
41: begin  st<= 30;  end 


ISSUE_CMD + 0  : begin  CSN<=0; SCK<=0;MO<=A[7];st<=st+1;end
ISSUE_CMD + 1  : begin  CSN<=0; SCK<=1;MO<=A[7];st<=st+1;end
ISSUE_CMD + 2  : begin  CSN<=0; SCK<=0;MO<=A[6];st<=st+1;end
ISSUE_CMD + 3  : begin  CSN<=0; SCK<=1;MO<=A[6];st<=st+1;end
ISSUE_CMD + 4  : begin  CSN<=0; SCK<=0;MO<=A[5];st<=st+1;end
ISSUE_CMD + 5  : begin  CSN<=0; SCK<=1;MO<=A[5];st<=st+1;end
ISSUE_CMD + 6  : begin  CSN<=0; SCK<=0;MO<=A[4];st<=st+1;end
ISSUE_CMD + 7  : begin  CSN<=0; SCK<=1;MO<=A[4];st<=st+1;end
ISSUE_CMD + 8  : begin  CSN<=0; SCK<=0;MO<=A[3];st<=st+1;end
ISSUE_CMD + 9  : begin  CSN<=0; SCK<=1;MO<=A[3];st<=st+1;end
ISSUE_CMD + 10 : begin  CSN<=0; SCK<=0;MO<=A[2];st<=st+1;end
ISSUE_CMD + 11 : begin  CSN<=0; SCK<=1;MO<=A[2];st<=st+1;end
ISSUE_CMD + 12 : begin  CSN<=0; SCK<=0;MO<=A[1];st<=st+1;end
ISSUE_CMD + 13 : begin  CSN<=0; SCK<=1;MO<=A[1];st<=st+1;end
ISSUE_CMD + 14 : begin  CSN<=0; SCK<=0;MO<=A[0];st<=st+1;end
ISSUE_CMD + 15 : begin  CSN<=0; SCK<=1;MO<=A[0];st<=st+1;end
ISSUE_CMD + 16 : begin  CSN<=0; SCK<=0;if (MIr)st<=st+1;end
ISSUE_CMD + 17 : st<=st+1;
ISSUE_CMD + 18 : st<=st+1;
ISSUE_CMD + 19 : begin CSN<=1; st<=st+1;end 
ISSUE_CMD + 20 : st<=st+1;
ISSUE_CMD + 21 : st <= RET_ST; 

 
 
RD_U16 + 0  : begin  CSN<=0; SCK<=0;MO<=A[7];st<=st+1;end
RD_U16 + 1  : begin  CSN<=0; SCK<=1;MO<=A[7];st<=st+1;end
RD_U16 + 2  : begin  CSN<=0; SCK<=0;MO<=A[6];st<=st+1;end
RD_U16 + 3  : begin  CSN<=0; SCK<=1;MO<=A[6];st<=st+1;end
RD_U16 + 4  : begin  CSN<=0; SCK<=0;MO<=A[5];st<=st+1;end
RD_U16 + 5  : begin  CSN<=0; SCK<=1;MO<=A[5];st<=st+1;end
RD_U16 + 6  : begin  CSN<=0; SCK<=0;MO<=A[4];st<=st+1;end
RD_U16 + 7  : begin  CSN<=0; SCK<=1;MO<=A[4];st<=st+1;end
RD_U16 + 8  : begin  CSN<=0; SCK<=0;MO<=A[3];st<=st+1;end
RD_U16 + 9  : begin  CSN<=0; SCK<=1;MO<=A[3];st<=st+1;end
RD_U16 + 10 : begin  CSN<=0; SCK<=0;MO<=A[2];st<=st+1;end
RD_U16 + 11 : begin  CSN<=0; SCK<=1;MO<=A[2];st<=st+1;end
RD_U16 + 12 : begin  CSN<=0; SCK<=0;MO<=A[1];st<=st+1;end
RD_U16 + 13 : begin  CSN<=0; SCK<=1;MO<=A[1];st<=st+1;end
RD_U16 + 14 : begin  CSN<=0; SCK<=0;MO<=A[0];st<=st+1;end
RD_U16 + 15 : begin  CSN<=0; SCK<=1;MO<=A[0];st<=st+1;end

RD_U16 + 16 : begin  CSN<=0; SCK<=0;R[7+8]<=MIr; st<=st+1;MO<=0;end
RD_U16 + 17 : begin  CSN<=0; SCK<=1;R[7+8]<=MIr; st<=st+1;end
RD_U16 + 18 : begin  CSN<=0; SCK<=0;R[6+8]<=MIr; st<=st+1;end
RD_U16 + 19 : begin  CSN<=0; SCK<=1;R[6+8]<=MIr; st<=st+1;end
RD_U16 + 20 : begin  CSN<=0; SCK<=0;R[5+8]<=MIr; st<=st+1;end
RD_U16 + 21 : begin  CSN<=0; SCK<=1;R[5+8]<=MIr; st<=st+1;end
RD_U16 + 22 : begin  CSN<=0; SCK<=0;R[4+8]<=MIr; st<=st+1;end
RD_U16 + 23 : begin  CSN<=0; SCK<=1;R[4+8]<=MIr; st<=st+1;end
RD_U16 + 24 : begin  CSN<=0; SCK<=0;R[3+8]<=MIr; st<=st+1;end
RD_U16 + 25 : begin  CSN<=0; SCK<=1;R[3+8]<=MIr; st<=st+1;end
RD_U16 + 26 : begin  CSN<=0; SCK<=0;R[2+8]<=MIr; st<=st+1;end
RD_U16 + 27 : begin  CSN<=0; SCK<=1;R[2+8]<=MIr; st<=st+1;end
RD_U16 + 28 : begin  CSN<=0; SCK<=0;R[1+8]<=MIr; st<=st+1;end
RD_U16 + 29 : begin  CSN<=0; SCK<=1;R[1+8]<=MIr; st<=st+1;end
RD_U16 + 30 : begin  CSN<=0; SCK<=0;R[0+8]<=MIr; st<=st+1;end
RD_U16 + 31 : begin  CSN<=0; SCK<=1;R[0+8]<=MIr; st<=st+1;end

RD_U16 + 32 : begin  CSN<=0; SCK<=0;R[7]<=MIr; st<=st+1;end
RD_U16 + 33 : begin  CSN<=0; SCK<=1;R[7]<=MIr; st<=st+1;end
RD_U16 + 34 : begin  CSN<=0; SCK<=0;R[6]<=MIr; st<=st+1;end
RD_U16 + 35 : begin  CSN<=0; SCK<=1;R[6]<=MIr; st<=st+1;end
RD_U16 + 36 : begin  CSN<=0; SCK<=0;R[5]<=MIr; st<=st+1;end
RD_U16 + 37 : begin  CSN<=0; SCK<=1;R[5]<=MIr; st<=st+1;end
RD_U16 + 38 : begin  CSN<=0; SCK<=0;R[4]<=MIr; st<=st+1;end
RD_U16 + 39 : begin  CSN<=0; SCK<=1;R[4]<=MIr; st<=st+1;end
RD_U16 + 40 : begin  CSN<=0; SCK<=0;R[3]<=MIr; st<=st+1;end
RD_U16 + 41 : begin  CSN<=0; SCK<=1;R[3]<=MIr; st<=st+1;end
RD_U16 + 42 : begin  CSN<=0; SCK<=0;R[2]<=MIr; st<=st+1;end
RD_U16 + 43 : begin  CSN<=0; SCK<=1;R[2]<=MIr; st<=st+1;end
RD_U16 + 44 : begin  CSN<=0; SCK<=0;R[1]<=MIr; st<=st+1;end
RD_U16 + 45 : begin  CSN<=0; SCK<=1;R[1]<=MIr; st<=st+1;end
RD_U16 + 46 : begin  CSN<=0; SCK<=0;R[0]<=MIr; st<=st+1;end
RD_U16 + 47 : begin  CSN<=0; SCK<=1;R[0]<=MIr; st<=st+1;end

RD_U16 + 48 :  begin SCK<=0;st<=st+1;end 
RD_U16 + 49 :  st<=st+1;
RD_U16 + 50 : begin CSN<=1;st<=st+1;end 
RD_U16 + 51 :  st<=st+1;
RD_U16 + 52 :  st <= RET_ST; 

   
RD_U24 + 0  : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 1  : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 2  : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 3  : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 4  : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 5  : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 6  : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 7  : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 8  : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 9  : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 10 : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 11 : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 12 : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 13 : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end
RD_U24 + 14 : begin  CSN<=0; SCK<=0;MO<=0;st<=st+1;end
RD_U24 + 15 : begin  CSN<=0; SCK<=1;MO<=0;st<=st+1;end

RD_U24 + 16 : begin  CSN<=0; SCK<=0;R[7+8+8]<=MIr; st<=st+1;end
RD_U24 + 17 : begin  CSN<=0; SCK<=1;R[7+8+8]<=MIr; st<=st+1;end
RD_U24 + 18 : begin  CSN<=0; SCK<=0;R[6+8+8]<=MIr; st<=st+1;end
RD_U24 + 19 : begin  CSN<=0; SCK<=1;R[6+8+8]<=MIr; st<=st+1;end
RD_U24 + 20 : begin  CSN<=0; SCK<=0;R[5+8+8]<=MIr; st<=st+1;end
RD_U24 + 21 : begin  CSN<=0; SCK<=1;R[5+8+8]<=MIr; st<=st+1;end
RD_U24 + 22 : begin  CSN<=0; SCK<=0;R[4+8+8]<=MIr; st<=st+1;end
RD_U24 + 23 : begin  CSN<=0; SCK<=1;R[4+8+8]<=MIr; st<=st+1;end
RD_U24 + 24 : begin  CSN<=0; SCK<=0;R[3+8+8]<=MIr; st<=st+1;end
RD_U24 + 25 : begin  CSN<=0; SCK<=1;R[3+8+8]<=MIr; st<=st+1;end
RD_U24 + 26 : begin  CSN<=0; SCK<=0;R[2+8+8]<=MIr; st<=st+1;end
RD_U24 + 27 : begin  CSN<=0; SCK<=1;R[2+8+8]<=MIr; st<=st+1;end
RD_U24 + 28 : begin  CSN<=0; SCK<=0;R[1+8+8]<=MIr; st<=st+1;end
RD_U24 + 29 : begin  CSN<=0; SCK<=1;R[1+8+8]<=MIr; st<=st+1;end
RD_U24 + 30 : begin  CSN<=0; SCK<=0;R[0+8+8]<=MIr; st<=st+1;end
RD_U24 + 31 : begin  CSN<=0; SCK<=1;R[0+8+8]<=MIr; st<=st+1;end

RD_U24 + 32 : begin  CSN<=0; SCK<=0;R[7+8]<=MIr; st<=st+1;end
RD_U24 + 33 : begin  CSN<=0; SCK<=1;R[7+8]<=MIr; st<=st+1;end
RD_U24 + 34 : begin  CSN<=0; SCK<=0;R[6+8]<=MIr; st<=st+1;end
RD_U24 + 35 : begin  CSN<=0; SCK<=1;R[6+8]<=MIr; st<=st+1;end
RD_U24 + 36 : begin  CSN<=0; SCK<=0;R[5+8]<=MIr; st<=st+1;end
RD_U24 + 37 : begin  CSN<=0; SCK<=1;R[5+8]<=MIr; st<=st+1;end
RD_U24 + 38 : begin  CSN<=0; SCK<=0;R[4+8]<=MIr; st<=st+1;end
RD_U24 + 39 : begin  CSN<=0; SCK<=1;R[4+8]<=MIr; st<=st+1;end
RD_U24 + 40 : begin  CSN<=0; SCK<=0;R[3+8]<=MIr; st<=st+1;end
RD_U24 + 41 : begin  CSN<=0; SCK<=1;R[3+8]<=MIr; st<=st+1;end
RD_U24 + 42 : begin  CSN<=0; SCK<=0;R[2+8]<=MIr; st<=st+1;end
RD_U24 + 43 : begin  CSN<=0; SCK<=1;R[2+8]<=MIr; st<=st+1;end
RD_U24 + 44 : begin  CSN<=0; SCK<=0;R[1+8]<=MIr; st<=st+1;end
RD_U24 + 45 : begin  CSN<=0; SCK<=1;R[1+8]<=MIr; st<=st+1;end
RD_U24 + 46 : begin  CSN<=0; SCK<=0;R[0+8]<=MIr; st<=st+1;end
RD_U24 + 47 : begin  CSN<=0; SCK<=1;R[0+8]<=MIr; st<=st+1;end


RD_U24 + 48 : begin  CSN<=0; SCK<=0;R[7]<=MIr; st <= st + 1;end
RD_U24 + 49 : begin  CSN<=0; SCK<=1;R[7]<=MIr; st <= st + 1;end
RD_U24 + 50 : begin  CSN<=0; SCK<=0;R[6]<=MIr; st <= st + 1;end
RD_U24 + 51 : begin  CSN<=0; SCK<=1;R[6]<=MIr; st <= st + 1;end
RD_U24 + 52 : begin  CSN<=0; SCK<=0;R[5]<=MIr; st <= st + 1;end
RD_U24 + 53 : begin  CSN<=0; SCK<=1;R[5]<=MIr; st <= st + 1;end
RD_U24 + 54 : begin  CSN<=0; SCK<=0;R[4]<=MIr; st <= st + 1;end
RD_U24 + 55 : begin  CSN<=0; SCK<=1;R[4]<=MIr; st <= st + 1;end
RD_U24 + 56 : begin  CSN<=0; SCK<=0;R[3]<=MIr; st <= st + 1;end
RD_U24 + 57 : begin  CSN<=0; SCK<=1;R[3]<=MIr; st <= st + 1;end
RD_U24 + 58 : begin  CSN<=0; SCK<=0;R[2]<=MIr; st <= st + 1;end
RD_U24 + 59 : begin  CSN<=0; SCK<=1;R[2]<=MIr; st <= st + 1;end
RD_U24 + 60 : begin  CSN<=0; SCK<=0;R[1]<=MIr; st <= st + 1;end
RD_U24 + 61 : begin  CSN<=0; SCK<=1;R[1]<=MIr; st <= st + 1;end
RD_U24 + 62 : begin  CSN<=0; SCK<=0;R[0]<=MIr; st <= st + 1;end
RD_U24 + 63 : begin  CSN<=0; SCK<=1;R[0]<=MIr; st <= st + 1;end


RD_U24 + 64 : begin SCK<=0;st<=st+1;end
RD_U24 + 65 :  st<=st+1;
RD_U24 + 66 :  begin CSN<=1;st<=st+1;end 
RD_U24 + 67 :  st<=st+1;
RD_U24 + 68 :  st <= RET_ST; 

default st<=0; 
endcase 
  
endmodule 

我们看到这个控制器在开始运行后发送一个复位命令，之后从PROM里面读出6个16位校准字传输出去（Q是数据输出，Q_WR是Q有效写的指示，可以接在一个队列里面），再之后就检测strat_rd u24信号，如果此信号有效则

1，启动转换D1命令并等待执行完毕，

2，读出D1并通过Q和Q_WR传输出去。

3，启动转换D2命令并等待执行完毕，

4，读出D2并通过Q和Q_WR传输出去。

这四个操作中1，3调用了ISSUE_CMD“函数”，2，4调用了RD_U24“函数“，这就实现了很好的复用性，函数优势体现出来了。

下一个BLOG我 写一下这个控制器如何连接FIFO队列，以及如何接入AXI_LITE外设核。再下一篇我简单写一下在PS里面如何控制这个核，最后写写如何实现温度气压的运算。