(一)参考学习资料
(二)实际操作
1. 相关变量计算:
First Initial |
Second Initial |
|||
Upper case |
H |
X |
||
ASCII (Dec) |
72 |
88 |
||
Lengths of the pulse |
||||
Mu |
Mu_1 |
2.5*105 |
Mu_2 |
2.5*105 |
k : mu |
ku_1 : mu_1 |
1.2812:3.7188 |
ku_2 : mu_2 |
1.3438:3.6562 |
nu |
nu_1 |
18 |
nu_2 |
18 |
Ku |
Ku_1 |
64060 |
Ku_2 |
67190 |
Lower case |
h |
x |
||
ASCII (Dec) |
104 |
120 |
||
Lengths of the pulse |
||||
Ml |
Ml_1 |
2.5*105 |
Ml_2 |
2.5*105 |
k : ml |
kl_1 : ml_1 |
1.4063:3.5937 |
k : ml_2 |
1.4688:3.5312 |
nl |
nl_1 |
18 |
nl_2 |
18 |
Kl |
Kl_1 |
70315 |
Kl_2 |
73440 |
2. 第一版:
1 module Assignment2(rst, CP, Z); 2 input CP; 3 input rst; //1 for upper & 0 for lower 4 5 reg turn = 0; 6 reg [1:0] cyc = 0; //use for the number of cycles 7 8 //constant parameters 9 parameter k = 100, n = 8, K = 100; 10 parameter KK = K-1; 11 12 //take parameters according to rst input 13 reg [7:0] M; 14 reg [7:0] MM; 15 reg [4:0] m; 16 //output of the lautch 17 output Z; 18 reg Z; 19 20 21 //parameters of upper case 22 parameter [7:0] Mu [0:1] = {128, 134}; 23 parameter [4:0] mu [0:1] = {28, 34}; 24 //parameter Ku_1 = k*Mu_1/(k+mu_1); 25 parameter [7:0] MMu [0:1] = {127, 133}; 26 //Parameter []KKu_1 = Ku_1-1; 27 34 //parameters of lower case 35 parameter [7:0] Ml [0:1] = {141, 147}; 36 parameter [4:0] ml [0:1] = {41, 47}; 37 parameter [7:0] MMl [0:1] = {127, 133}; 38 39 //Check rst to determine upper or lower. 40 //check the number of turn to determine the first two or the second. 41 always@(posedge CP) 42 begin 43 if(rst) 44 begin 45 M <= turn ? Mu[1]:Mu[0]; 46 m <= turn ? mu[1]:mu[0]; 47 MM <= turn ? MMu[1]:MMu[0]; 48 end 49 else if(!rst) 50 begin 51 M <= turn ? Ml[1]:Ml[0]; 52 m <= turn ? ml[1]:ml[0]; 53 MM <= turn ? MMl[1]:MMl[0]; 54 end 55 end 56 57 //Latch 58 reg [n-1:0] Q = 0; 59 wire ld, cz; 60 assign ld = Q>=MM; 61 assign cz = (Q<KK)|ld; 62 63 always@(posedge CP) 64 begin 65 {Q,Z} <= {ld?0:Q+1, cz}; 66 cyc = ld ? cyc+1 : cyc; 67 68 if(cyc == 2) 69 begin 70 turn <= 1; 71 cyc <= 0; 72 end 73 else begin 74 turn <= 0; 75 end 76 end 77 78 79 endmodule
- 出现问题1:
解决方案:将如下部分的变量类型由reg改为了input,系统没有再次崩溃。
12 //take parameters according to rst input 13 reg [7:0] M; 14 reg [7:0] MM; 15 reg [4:0] m; 16 //output of the lautch 17 output Z; 18 reg Z;
原因:不明
补充:reg变量不可按位赋值,在二维数组中的赋值应为下图第一种方法。
// Correct M <=Mu[1]; // WrongM <=Mu[1][7:0];
- 出现问题2:vwf文件仿真时,M没有成功赋值
解决方案:修正了对reg宽度的定义。
补充:
1. Verilog中reg类型的宽度是自定义的,若无定义则默认为1bit。reg的宽度影响变量的取值,若赋值超出reg的范围,不会产生Error,reg变量的最大值将被默认为reg宽度。修改变量时应注意该变量的取值范围。
2. reg变量只能存储整数,允许的运算为加减乘除,若要实现浮点数需要以此为基础构建相关专门的模块。
3. 第二版:
1 module Assignment2(rst, CP, Z, K); 2 input CP; 3 input rst; //1 for upper & 0 for lower 4 5 reg turn = 0; 6 //use to determine whether the first group of pulses or the second one 7 reg [3:0] cyc = 0; 8 //use for the number of pulses in one ‘turn‘ 9 10 ////constant parameters 11 parameter n = 18, M = 250000; 12 parameter MM = M-1; 13 14 ////take parameters according to rst input 15 output [n-1:0] K; 16 reg [n-1:0] K = 0; 17 18 ////output of the lautch 19 output Z; 20 reg Z; 21 22 ////parameters of upper case 23 parameter Ku_1 = 64060; 24 parameter Ku_2 = 67190; 25 26 ////parameters of lower case 27 parameter Kl_1 = 70315; 28 parameter Kl_2 = 73440; 29 30 ////Latch 31 reg [n-1:0] Q; 32 wire ld, cz; 33 assign ld = Q>=MM; 34 assign cz = (Q<K-1)|ld; 35 36 always@(posedge CP) 37 begin 38 ////Check rst to determine upper or lower. 39 ////check the number of turn to determine the first two or the second. 40 case(rst) 41 0: begin 42 if(turn)K <= Kl_2; 43 else if(!turn)K <= Kl_1; 44 else K <= 100; 45 end 46 1: begin 47 if(turn)K <= Ku_2; 48 else if(!turn)K <= Ku_1; 49 else K <= 200; 50 end 51 default: K <= 9999999; 52 endcase 53 54 ////renew the state and output clock. 55 {Q,Z} <= {ld?0:Q+1, cz}; 56 cyc = ld ? cyc+1 : cyc; 57 58 ////1 cyc represent a pulse 59 ////2 cycles cause an increment in turn 60 ////4 cycles for an entire loop 61 if(cyc == 2) 62 begin 63 turn <= 1; 64 end 65 else if(cyc==4 && turn==1) 66 begin 67 turn <= 0; 68 cyc <= 0; 69 end 70 71 end 72 73 endmodule
- 仿真结果://K的取值有修改。
- 补充:在Z的第一个输出前有一小段空白期,测量为微秒级,第一个输出仍为5ms。感觉应该不影响时钟的使用,但没有经过硬件检测。
原文地址:https://www.cnblogs.com/schelling/p/12368335.html
时间: 2024-10-01 06:46:17