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[/] [openrisc/] [trunk/] [or1200/] [rtl/] [verilog/] [or1200_alu.v] - Diff between revs 10 and 141

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Rev 10 Rev 141
Line 41... Line 41... 
////                                                              ////
 
////                                                              ////
 
//////////////////////////////////////////////////////////////////////
 
//////////////////////////////////////////////////////////////////////
 
//
 
//
 
// CVS Revision History
 
// CVS Revision History
 
//
 
//
 
// $Log: not supported by cvs2svn $
 
// $Log: or1200_alu.v,v $
 
 
 
// Revision 2.0  2010/06/30 11:00:00  ORSoC
 
 
 
// Minor update: 
 
 
// Defines added, flags are corrected. 
 
 
//
 
 
 
// Revision 1.15  2005/01/07 09:23:39  andreje
 
 
 
// l.ff1 and l.cmov instructions added
 
 
 
//
 
// Revision 1.14  2004/06/08 18:17:36  lampret
 
// Revision 1.14  2004/06/08 18:17:36  lampret
 
// Non-functional changes. Coding style fixes.
 
// Non-functional changes. Coding style fixes.
 
//
 
//
 
// Revision 1.13  2004/05/09 19:49:03  lampret
 
// Revision 1.13  2004/05/09 19:49:03  lampret
 
// Added some l.cust5 custom instructions as example
 
// Added some l.cust5 custom instructions as example
Line 165... Line 172... 
wire    [width-1:0]              result_csum;
 
wire    [width-1:0]              result_csum;
 
wire                            cy_csum;
 
wire                            cy_csum;
 
`endif
 
`endif
 
wire    [width-1:0]              result_and;
 
wire    [width-1:0]              result_and;
 
wire                            cy_sum;
 
wire                            cy_sum;
 
 
 
`ifdef OR1200_IMPL_SUB
 
 
 
wire                            cy_sub;
 
 
 
`endif
 
reg                             cyforw;
 
reg                             cyforw;
 
 
 
 
 
//
 
//
 
// Combinatorial logic
 
// Combinatorial logic
 
//
 
//
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assign comp_b = {b[width-1] ^ comp_op[3] , b[width-2:0]};
 
assign comp_b = {b[width-1] ^ comp_op[3] , b[width-2:0]};
 
`ifdef OR1200_IMPL_ALU_COMP1
 
`ifdef OR1200_IMPL_ALU_COMP1
 
assign a_eq_b = (comp_a == comp_b);
 
assign a_eq_b = (comp_a == comp_b);
 
assign a_lt_b = (comp_a < comp_b);
 
assign a_lt_b = (comp_a < comp_b);
 
`endif
 
`endif
 
 
 
`ifdef OR1200_IMPL_SUB
 
 
 
assign cy_sub = a < b;
 
 
 
`endif
 
assign {cy_sum, result_sum} = a + b;
 
assign {cy_sum, result_sum} = a + b;
 
`ifdef OR1200_IMPL_ADDC
 
`ifdef OR1200_IMPL_ADDC
 
assign {cy_csum, result_csum} = a + b + {32'd0, carry};
 
assign {cy_csum, result_csum} = a + b + {`OR1200_OPERAND_WIDTH'd0, carry};
 
`endif
 
`endif
 
assign result_and = a & b;
 
assign result_and = a & b;
 
 
 
 
 
//
 
//
 
// Simulation check for bad ALU behavior
 
// Simulation check for bad ALU behavior
Line 197... Line 210... 
`endif
 
`endif
 
 
 
 
 
//
 
//
 
// Central part of the ALU
 
// Central part of the ALU
 
//
 
//
 
always @(alu_op or a or b or result_sum or result_and or macrc_op or shifted_rotated or mult_mac_result) begin
 
always @(alu_op or a or b or result_sum or result_and or macrc_op or shifted_rotated or mult_mac_result or flag or result_cust5 or carry
 
 
 
`ifdef OR1200_IMPL_ADDC
 
 
 
         or result_csum
 
 
 
`endif
 
 
 
) begin
 
`ifdef OR1200_CASE_DEFAULT
 
`ifdef OR1200_CASE_DEFAULT
 
        casex (alu_op)          // synopsys parallel_case
 
        casex (alu_op)          // synopsys parallel_case
 
`else
 
`else
 
        casex (alu_op)          // synopsys full_case parallel_case
 
        casex (alu_op)          // synopsys full_case parallel_case
 
`endif
 
`endif
Line 220... Line 237... 
`ifdef OR1200_IMPL_ADDC
 
`ifdef OR1200_IMPL_ADDC
 
                `OR1200_ALUOP_ADDC : begin
 
                `OR1200_ALUOP_ADDC : begin
 
                                result = result_csum;
 
                                result = result_csum;
 
                end
 
                end
 
`endif
 
`endif
 
 
 
`ifdef OR1200_IMPL_SUB
 
                `OR1200_ALUOP_SUB : begin
 
                `OR1200_ALUOP_SUB : begin
 
                                result = a - b;
 
                                result = a - b;
 
                end
 
                end
 
 
 
`endif
 
                `OR1200_ALUOP_XOR : begin
 
                `OR1200_ALUOP_XOR : begin
 
                                result = a ^ b;
 
                                result = a ^ b;
 
                end
 
                end
 
                `OR1200_ALUOP_OR  : begin
 
                `OR1200_ALUOP_OR  : begin
 
                                result = a | b;
 
                                result = a | b;
Line 256... Line 275... 
    end
 
    end
 
 
 
 
 
`ifdef OR1200_CASE_DEFAULT
 
`ifdef OR1200_CASE_DEFAULT
 
    default: begin
 
    default: begin
 
`else
 
`else
 
    `OR1200_ALUOP_COMP, `OR1200_ALUOP_AND:
 
                `OR1200_ALUOP_COMP, `OR1200_ALUOP_AND: begin
 
    begin
 
 
 
`endif
 
`endif
 
      result=result_and;
 
      result=result_and;
 
    end
 
    end
 
        endcase
 
        endcase
 
end
 
end
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end
 
end
 
 
 
 
 
//
 
//
 
// Generate flag and flag write enable
 
// Generate flag and flag write enable
 
//
 
//
 
always @(alu_op or result_sum or result_and or flagcomp) begin
 
always @(alu_op or result_sum or result_and or flagcomp
 
 
 
`ifdef OR1200_IMPL_ADDC
 
 
 
         or result_csum
 
 
 
`endif
 
 
 
) begin
 
        casex (alu_op)          // synopsys parallel_case
 
        casex (alu_op)          // synopsys parallel_case
 
`ifdef OR1200_ADDITIONAL_FLAG_MODIFIERS
 
`ifdef OR1200_ADDITIONAL_FLAG_MODIFIERS
 
                `OR1200_ALUOP_ADD : begin
 
                `OR1200_ALUOP_ADD : begin
 
                        flagforw = (result_sum == 32'h0000_0000);
 
                        flagforw = (result_sum == 32'h0000_0000);
 
                        flag_we = 1'b1;
 
                        flag_we = 1'b1;
Line 318... Line 340... 
                `OR1200_ALUOP_COMP: begin
 
                `OR1200_ALUOP_COMP: begin
 
                        flagforw = flagcomp;
 
                        flagforw = flagcomp;
 
                        flag_we = 1'b1;
 
                        flag_we = 1'b1;
 
                end
 
                end
 
                default: begin
 
                default: begin
 
                        flagforw = 1'b0;
 
                        flagforw = flagcomp;
 
                        flag_we = 1'b0;
 
                        flag_we = 1'b0;
 
                end
 
                end
 
        endcase
 
        endcase
 
end
 
end
 
 
 
 
 
//
 
//
 
// Generate SR[CY] write enable
 
// Generate SR[CY] write enable
 
//
 
//
 
always @(alu_op or cy_sum
 
always @(alu_op or cy_sum
 
 
 
`ifdef OR1200_IMPL_CY
 
`ifdef OR1200_IMPL_ADDC
 
`ifdef OR1200_IMPL_ADDC
 
        or cy_csum
 
        or cy_csum
 
`endif
 
`endif
 
 
 
`ifdef OR1200_IMPL_SUB
 
 
 
        or cy_sub
 
 
 
`endif
 
 
 
`endif
 
        ) begin
 
        ) begin
 
        casex (alu_op)          // synopsys parallel_case
 
        casex (alu_op)          // synopsys parallel_case
 
`ifdef OR1200_IMPL_CY
 
`ifdef OR1200_IMPL_CY
 
                `OR1200_ALUOP_ADD : begin
 
                `OR1200_ALUOP_ADD : begin
 
                        cyforw = cy_sum;
 
                        cyforw = cy_sum;
Line 344... Line 371... 
                `OR1200_ALUOP_ADDC: begin
 
                `OR1200_ALUOP_ADDC: begin
 
                        cyforw = cy_csum;
 
                        cyforw = cy_csum;
 
                        cy_we = 1'b1;
 
                        cy_we = 1'b1;
 
                end
 
                end
 
`endif
 
`endif
 
 
 
`ifdef OR1200_IMPL_SUB
 
 
 
                `OR1200_ALUOP_SUB: begin
 
 
 
                        cyforw = cy_sub;
 
 
 
                        cy_we = 1'b1;
 
 
 
                end
 
 
 
`endif
 
`endif
 
`endif
 
                default: begin
 
                default: begin
 
                        cyforw = 1'b0;
 
                        cyforw = 1'b0;
 
                        cy_we = 1'b0;
 
                        cy_we = 1'b0;
 
                end
 
                end

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