OpenCores
URL https://opencores.org/ocsvn/klc32/klc32/trunk

Subversion Repositories klc32

[/] [klc32/] [trunk/] [rtl/] [verilog/] [REGFETCHA.v] - Blame information for rev 4

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 robfinch
// ============================================================================
2
// (C) 2011 Robert Finch
3
// All Rights Reserved.
4
// robfinch<remove>@opencores.org
5
//
6
// KLC32 - 32 bit CPU
7
// REGFETCHA.v - fetch register A / execute some instructions
8
//
9
// This source file is free software: you can redistribute it and/or modify 
10
// it under the terms of the GNU Lesser General Public License as published 
11
// by the Free Software Foundation, either version 3 of the License, or     
12
// (at your option) any later version.                                      
13
//                                                                          
14
// This source file is distributed in the hope that it will be useful,      
15
// but WITHOUT ANY WARRANTY; without even the implied warranty of           
16
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            
17
// GNU General Public License for more details.                             
18
//                                                                          
19
// You should have received a copy of the GNU General Public License        
20
// along with this program.  If not, see <http://www.gnu.org/licenses/>.    
21
//                                                                          
22
// ============================================================================
23
//
24
REGFETCHA:
25
        begin
26
                a <= rfo;
27
                b <= 32'd0;
28
                Rn <= ir[20:16];
29
                if (opcode==`RR || opcode==`RRR) begin
30
                        state <= REGFETCHB;
31
                end
32
                else begin
33
                        if ((hasConst16 && ir[15:0]==16'h8000) || (isStop))
34
                                state <= FETCH_IMM32;
35
                        else begin
36
                                imm <= {{16{ir[15]}},ir[15:0]};
37
                                state <= EXECUTE;
38
                        end
39
                end
40
                case(opcode)
41
                `MISC:
42
                        case(func)
43
                        `TRACE_ON:
44
                                        if (!sf) begin
45
                                                vector <= `PRIVILEGE_VIOLATION;
46
                                                state <= TRAP;
47
                                        end
48
                                        else begin
49
                                                tf <= 1'b1;
50
                                                state <= IFETCH;
51
                                        end
52
                        `TRACE_OFF:
53
                                        if (!sf) begin
54
                                                vector <= `PRIVILEGE_VIOLATION;
55
                                                state <= TRAP;
56
                                        end
57
                                        else begin
58
                                                tf <= 1'b0;
59
                                                state <= IFETCH;
60
                                        end
61
                        `SET_IM:
62
                                        if (!sf) begin
63
                                                vector <= `PRIVILEGE_VIOLATION;
64
                                                state <= TRAP;
65
                                        end
66
                                        else begin
67
                                                im <= ir[2:0];
68
                                                state <= IFETCH;
69
                                        end
70
                        `USER_MODE: begin sf <= 1'b0; state <= IFETCH; end
71
                        `JMP32: state <= JMP32;
72
                        `JSR32: state <= JSR32;
73
                        `RTS: state <= RTS;
74
                        `RTI:
75
                                if (!sf) begin
76
                                        vector <= `PRIVILEGE_VIOLATION;
77
                                        state <= TRAP;
78
                                end
79
                                else
80
                                        state <= RTI1;
81
                        `RST:
82
                                if (!sf) begin
83
                                        vector <= `PRIVILEGE_VIOLATION;
84
                                        state <= TRAP;
85
                                end
86
                                else begin
87
                                        rst_o <= 1'b1;
88
                                        state <= IFETCH;
89
                                end
90
                        endcase
91
                `NOP: state <= IFETCH;
92
                `JSR: begin tgt <= {pc[31:26],ir[25:2],2'b00}; state <= JSR1; end
93
                `JMP: begin pc[25:2] <= ir[25:2]; state <= IFETCH; end
94
                `Bcc:
95
                        case(cond)
96
                        `BRA:   begin pc <= pc + brdisp; state <= IFETCH; end
97
                        `BEQ:   begin if ( cr_zf) pc <= pc + brdisp; state <= IFETCH; end
98
                        `BNE:   begin if (!cr_zf) pc <= pc + brdisp; state <= IFETCH; end
99
                        `BMI:   begin if ( cr_nf) pc <= pc + brdisp; state <= IFETCH; end
100
                        `BPL:   begin if (!cr_zf) pc <= pc + brdisp; state <= IFETCH; end
101
                        `BHI:   begin if (!cr_cf & !cr_zf) pc <= pc + brdisp; state <= IFETCH; end
102
                        `BLS:   begin if (cf |zf) pc <= pc + brdisp; state <= IFETCH; end
103
                        `BHS:   begin if (!cr_cf) pc <= pc + brdisp; state <= IFETCH; end
104
                        `BLO:   begin if ( cr_cf) pc <= pc + brdisp; state <= IFETCH; end
105
                        `BGT:   begin if ((cr_nf & cr_vf & !cr_zf)|(!cr_nf & !cr_vf & !cr_zf)) pc <= pc + brdisp; state <= IFETCH; end
106
                        `BLE:   begin if (cr_zf | (cr_nf & !cr_vf) | (!cr_nf & cr_vf)) pc <= pc + brdisp; state <= IFETCH; end
107
                        `BGE:   begin if ((cr_nf & cr_vf)|(!cr_nf & !cr_vf)) pc <= pc + brdisp; state <= IFETCH; end
108
                        `BLT:   begin if ((cr_nf & !cr_vf)|(!cr_nf & cr_vf)) pc <= pc + brdisp; state <= IFETCH; end
109
                        `BVS:   begin if ( cr_vf) pc <= pc + brdisp; state <= IFETCH; end
110
                        `BVC:   begin if (!cr_vf) pc <= pc + brdisp; state <= IFETCH; end
111
                        endcase
112
                `TRAPcc:
113
                        case(cond)
114
                        `TRAP:  begin vector <= `TRAP_VECTOR + {ir[3:0],2'b00}; state <= TRAP; end
115
                        `TEQ:   begin if ( cr_zf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
116
                        `TNE:   begin if (!cr_zf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
117
                        `TMI:   begin if ( cr_nf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
118
                        `TPL:   begin if (!cr_zf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
119
                        `THI:   begin if (!cr_cf & !cr_zf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
120
                        `TLS:   begin if (cf |zf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
121
                        `THS:   begin if (!cr_cf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
122
                        `TLO:   begin if ( cr_cf) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
123
                        `TGT:   begin if ((cr_nf & cr_vf & !cr_zf)|(!cr_nf & !cr_vf & !cr_zf)) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
124
                        `TLE:   begin if (cr_zf | (cr_nf & !cr_vf) | (!cr_nf & cr_vf)) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
125
                        `TGE:   begin if ((cr_nf & cr_vf)|(!cr_nf & !cr_vf)) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
126
                        `TLT:   begin if ((cr_nf & !cr_vf)|(!cr_nf & cr_vf)) begin vector <= `TRAP_VECTOR; state <= TRAP; end else state <= IFETCH; end
127
                        `TVS:   begin if ( cr_vf) begin vector <= `TRAPV_VECTOR; state <= TRAP; end else state <= IFETCH; end
128
                        `TVC:   begin if (!cr_vf) begin vector <= `TRAPV_VECTOR; state <= TRAP; end else state <= IFETCH; end
129
                        endcase
130
                `SETcc: Rn <= ir[15:11];
131
                `PUSH:  state <= PUSH1;
132
                `POP:   state <= POP1;
133
                `UNLK:  state <= UNLK;
134
                endcase
135
                if (isIllegalOpcode) begin
136
                        vector <= `ILLEGAL_INSN;
137
                        state <= TRAP;
138
                end
139
        end
140
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.