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[/] [rtf8088/] [trunk/] [rtl/] [verilog/] [EVALUATE_BRANCH.v] - Blame information for rev 2

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// ============================================================================
//  EVALUATE_BRANCH.v
//  Evaluate branch condition
//
//
//  (C) 2009,2010  Robert Finch
//  Stratford
//  robfinch[remove]@opencores.ca
//
//  
//  This source code is available for evaluation and validation purposes
//  only. This copyright statement and disclaimer must remain present in
//  the file.
//
//      NO WARRANTY.
//  THIS Work, IS PROVIDEDED "AS IS" WITH NO WARRANTIES OF ANY KIND, WHETHER
//  EXPRESS OR IMPLIED. The user must assume the entire risk of using the
//  Work.
//
//  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
//  INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES WHATSOEVER RELATING TO
//  THE USE OF THIS WORK, OR YOUR RELATIONSHIP WITH THE AUTHOR.
//
//  IN ADDITION, IN NO EVENT DOES THE AUTHOR AUTHORIZE YOU TO USE THE WORK
//  IN APPLICATIONS OR SYSTEMS WHERE THE WORK'S FAILURE TO PERFORM CAN
//  REASONABLY BE EXPECTED TO RESULT IN A SIGNIFICANT PHYSICAL INJURY, OR IN
//  LOSS OF LIFE. ANY SUCH USE BY YOU IS ENTIRELY AT YOUR OWN RISK, AND YOU
//  AGREE TO HOLD THE AUTHOR AND CONTRIBUTORS HARMLESS FROM ANY CLAIMS OR
//  LOSSES RELATING TO SUCH UNAUTHORIZED USE.
//
//
//  Verilog 
//
// ============================================================================
//
`ifndef JMPS
`define JMPS    8'hEB
`endif
 
`ifndef JO
`define JO              8'h70
`define JNO             8'h71
`define JB              8'h72
`define JAE             8'h73
`define JE              8'h74
`define JNE             8'h75
`define JBE             8'h76
`define JA              8'h77
`define JS              8'h78
`define JNS             8'h79
`define JP              8'h7A
`define JNP             8'h7B
`define JL              8'h7C
`define JNL             8'h7D
`define JLE             8'h7E
`define JNLE    8'h7F
 
`define JNA             8'h76
`define JNAE    8'h72
`define JNB     8'h73
`define JNBE    8'h77
`define JC      8'h72
`define JNC     8'h73
`define JG              8'h7F
`define JNG             8'h7E
`define JGE             8'h7D
`define JNGE    8'h7C
`define JPE     8'h7A
`define JPO     8'h7B
 
`define LOOPNZ  8'hE0
`define LOOPZ   8'hE1
`define LOOP    8'hE2
`define JCXZ    8'hE3
 
`endif
 
module evaluate_branch(ir,cx,zf,cf,sf,vf,pf,take_br);
input [7:0] ir;
input [15:0] cx;
input zf,cf,sf,vf,pf;
output take_br;
 
reg take_br;
wire cxo = cx==16'h0001;        // CX is one
wire cxz = cx==16'h0000;        // CX is zero
 
always @(ir or cx or cxz or cxo or zf or cf or sf or vf or pf)
        case(ir)
        `JMPS:          take_br <= 1'b1;
        `JP:            take_br <=  pf;
        `JNP:           take_br <= !pf;
        `JO:            take_br <=  vf;
        `JNO:           take_br <= !vf;
        `JE:            take_br <=  zf;
        `JNE:           take_br <= !zf;
        `JAE:           take_br <= !cf;
        `JB:            take_br <=  cf;
        `JS:            take_br <=  sf;
        `JNS:           take_br <= !sf;
        `JBE:           take_br <=  cf | zf;
        `JA:            take_br <= !cf & !zf;
        `JL:            take_br <= sf ^ vf;
        `JNL:           take_br <= !(sf ^ vf);
        `JLE:           take_br <= (sf ^ vf) | zf;
        `JNLE:          take_br <= !((sf ^ vf) | zf);
        `JCXZ:          take_br <= cxz;
        `LOOP:          take_br <= !cxo;
        `LOOPZ:         take_br <= !cxo && zf;
        `LOOPNZ:        take_br <= !cxo && !zf;
        default:        take_br <= 1'b0;
        endcase
 
endmodule

Line No.	Rev	Author	Line
1	2	robfinch	`// ============================================================================`
2			`// EVALUATE_BRANCH.v`
3			`// Evaluate branch condition`
4			`//`
5			`//`
6			`// (C) 2009,2010 Robert Finch`
7			`// Stratford`
8			`// robfinch[remove]@opencores.ca`
9			`//`
10			`//`
11			`// This source code is available for evaluation and validation purposes`
12			`// only. This copyright statement and disclaimer must remain present in`
13			`// the file.`
14			`//`
15			`// NO WARRANTY.`
16			`// THIS Work, IS PROVIDEDED "AS IS" WITH NO WARRANTIES OF ANY KIND, WHETHER`
17			`// EXPRESS OR IMPLIED. The user must assume the entire risk of using the`
18			`// Work.`
19			`//`
20			`// IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY`
21			`// INCIDENTAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES WHATSOEVER RELATING TO`
22			`// THE USE OF THIS WORK, OR YOUR RELATIONSHIP WITH THE AUTHOR.`
23			`//`
24			`// IN ADDITION, IN NO EVENT DOES THE AUTHOR AUTHORIZE YOU TO USE THE WORK`
25			`// IN APPLICATIONS OR SYSTEMS WHERE THE WORK'S FAILURE TO PERFORM CAN`
26			`// REASONABLY BE EXPECTED TO RESULT IN A SIGNIFICANT PHYSICAL INJURY, OR IN`
27			`// LOSS OF LIFE. ANY SUCH USE BY YOU IS ENTIRELY AT YOUR OWN RISK, AND YOU`
28			`// AGREE TO HOLD THE AUTHOR AND CONTRIBUTORS HARMLESS FROM ANY CLAIMS OR`
29			`// LOSSES RELATING TO SUCH UNAUTHORIZED USE.`
30			`//`
31			`//`
32			`// Verilog`
33			`//`
34			`// ============================================================================`
35			`//`
36			`ifndef JMPS
37			`define JMPS 8'hEB
38			`endif
39
40			`ifndef JO
41			`define JO 8'h70
42			`define JNO 8'h71
43			`define JB 8'h72
44			`define JAE 8'h73
45			`define JE 8'h74
46			`define JNE 8'h75
47			`define JBE 8'h76
48			`define JA 8'h77
49			`define JS 8'h78
50			`define JNS 8'h79
51			`define JP 8'h7A
52			`define JNP 8'h7B
53			`define JL 8'h7C
54			`define JNL 8'h7D
55			`define JLE 8'h7E
56			`define JNLE 8'h7F
57
58			`define JNA 8'h76
59			`define JNAE 8'h72
60			`define JNB 8'h73
61			`define JNBE 8'h77
62			`define JC 8'h72
63			`define JNC 8'h73
64			`define JG 8'h7F
65			`define JNG 8'h7E
66			`define JGE 8'h7D
67			`define JNGE 8'h7C
68			`define JPE 8'h7A
69			`define JPO 8'h7B
70
71			`define LOOPNZ 8'hE0
72			`define LOOPZ 8'hE1
73			`define LOOP 8'hE2
74			`define JCXZ 8'hE3
75
76			`endif
77
78			`module evaluate_branch(ir,cx,zf,cf,sf,vf,pf,take_br);`
79			`input [7:0] ir;`
80			`input [15:0] cx;`
81			`input zf,cf,sf,vf,pf;`
82			`output take_br;`
83
84			`reg take_br;`
85			`wire cxo = cx==16'h0001; // CX is one`
86			`wire cxz = cx==16'h0000; // CX is zero`
87
88			`always @(ir or cx or cxz or cxo or zf or cf or sf or vf or pf)`
89			`case(ir)`
90			`JMPS: take_br <= 1'b1;
91			`JP: take_br <= pf;
92			`JNP: take_br <= !pf;
93			`JO: take_br <= vf;
94			`JNO: take_br <= !vf;
95			`JE: take_br <= zf;
96			`JNE: take_br <= !zf;
97			`JAE: take_br <= !cf;
98			`JB: take_br <= cf;
99			`JS: take_br <= sf;
100			`JNS: take_br <= !sf;
101			`JBE: take_br <= cf \| zf;
102			`JA: take_br <= !cf & !zf;
103			`JL: take_br <= sf ^ vf;
104			`JNL: take_br <= !(sf ^ vf);
105			`JLE: take_br <= (sf ^ vf) \| zf;
106			`JNLE: take_br <= !((sf ^ vf) \| zf);
107			`JCXZ: take_br <= cxz;
108			`LOOP: take_br <= !cxo;
109			`LOOPZ: take_br <= !cxo && zf;
110			`LOOPNZ: take_br <= !cxo && !zf;
111			`default: take_br <= 1'b0;`
112			`endcase`
113
114			`endmodule`

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[/] [rtf8088/] [trunk/] [rtl/] [verilog/] [EVALUATE_BRANCH.v] - Blame information for rev 2