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Adding proper read alignment for ememory model

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-Byte/shorts now work
This commit is contained in:
Andreas Olofsson 2015-11-12 10:49:40 -05:00
parent 8820c8500a
commit 847eae23ab
2 changed files with 138 additions and 16 deletions
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30
emesh/dv/ememory.v
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@ -44,7 +44,7 @@ module ememory(/*AUTOARG*/
wire [AW-1:0] srcaddr_out;
wire [AW-1:0] data_out;
reg hilo_sel;
reg [2:0] align_addr;
wire write_in;
wire [1:0] datamode_in;
@ -52,8 +52,8 @@ module ememory(/*AUTOARG*/
wire [AW-1:0] dstaddr_in;
wire [DW-1:0] data_in;
wire [AW-1:0] srcaddr_in;
wire [DW-1:0] data_align;
wire [DW-1:0] din_aligned;
wire [DW-1:0] dout_aligned;
packet2emesh #(.PW(PW))
p2e (
@ -79,13 +79,13 @@ module ememory(/*AUTOARG*/
assign addr[MAW-1:0] = dstaddr_in[MAW+2:3];
//Shift up
assign data_align[DW-1:0] = (datamode_in[1:0]==2'b00) ? {(4){data_in[7:0]}} :
assign din_aligned[DW-1:0] = (datamode_in[1:0]==2'b00) ? {(4){data_in[7:0]}} :
(datamode_in[1:0]==2'b01) ? {(2){data_in[15:0]}} :
data_in[31:0];
//Data-in (hardoded width)
assign din[63:0] =(datamode_in[1:0]==2'b11) ? {srcaddr_in[31:0],data_align[31:0]}:
{data_align[31:0],data_align[31:0]};
assign din[63:0] =(datamode_in[1:0]==2'b11) ? {srcaddr_in[31:0],din_aligned[31:0]}:
{din_aligned[31:0],din_aligned[31:0]};
//Write mask
always@*
casez({write_in, datamode_in[1:0],dstaddr_in[2:0]})
@ -136,19 +136,23 @@ module ememory(/*AUTOARG*/
if(mem_rd & ~wait_in)
begin
write_out <= 1'b1;
hilo_sel <= dstaddr_in[2];
align_addr[2:0] <= dstaddr_in[2:0];
datamode_out[1:0] <= datamode_in[1:0];
ctrlmode_out[4:0] <= ctrlmode_in[3:0];
dstaddr_out[AW-1:0] <= srcaddr_in[AW-1:0];
end
assign srcaddr_out[AW-1:0] = dout[63:32];
//Data alignment for readback
emesh_rdalign emesh_rdalign (// Outputs
.data_out (dout_aligned[DW-1:0]),
// Inputs
.datamode (datamode_out[1:0]),
.addr (align_addr[2:0]),
.data_in (dout[2*DW-1:0]));
//note sure about this???
assign data_out[DW-1:0] = hilo_sel ? dout[63:32] :
dout[31:0];
assign srcaddr_out[AW-1:0] = dout_aligned[63:32];
assign data_out[DW-1:0] = dout_aligned[31:0];
//Concatenate
emesh2packet #(.PW(PW))
@ -178,7 +182,7 @@ module ememory(/*AUTOARG*/
endmodule // emesh_memory
// Local Variables:
// verilog-library-directories:("." "../dv" )
// verilog-library-directories:("." "../hdl" )
// End:

118
emesh/hdl/emesh_rdalign.v Normal file
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@ -0,0 +1,118 @@
/*The Epiphany memory model assumes the following alignment on incoming transactions*/
//Byte Mode:
//ADDR[2:0] B7 B6 B5 B4 B3 B2 B1 B0
//x00 0 0 0 MB0 0 0 0 MB0
//x01 0 0 0 MB1 0 0 0 MB1
//x10 0 0 0 MB2 0 0 0 MB2
//x11 0 0 0 MB3 0 0 0 MB3
//Short Mode:
//ADDR[2:0] B7 B6 B5 B4 B3 B2 B1 B0
//x00 0 0 MB1 MB0 0 0 MB1 MB0
//x10 0 0 MB3 MB2 0 0 MB3 MB2
//Word Mode:
//ADDR[2:0] B7 B6 B5 B4 B3 B2 B1 B0
//x00 MB3 MB2 MB1 MB0 MB3 MB2 MB1 MB0
//Double Mode:
//ADDR[2:0] B7 B6 B5 B4 B3 B2 B1 B0
//000 MB7 MB6 MB5 MB4 MB3 MB2 MB1 MB0
module emesh_rdalign (/*AUTOARG*/
// Outputs
data_out,
// Inputs
datamode, addr, data_in
);
parameter DW = 32;
//Inputs
input [1:0] datamode;
input [2:0] addr;
input [2*DW-1:0] data_in;
//Outputs
output [DW-1:0] data_out;
//wires
wire [DW-1:0] data_low;
//wires
/* verilator lint_off UNOPTFLAT */
wire [3:0] byte0_sel;
/* verilator lint_on UNOPTFLAT */
wire [3:0] byte1_sel;
wire [3:0] byte2_sel;
wire [3:0] byte3_sel;
wire [31:0] data_mux;
wire [31:0] data_aligned;
assign data_mux[31:0] = ((addr[2] & (datamode[1:0]!=2'b11))) ? data_in[2*DW-1:DW] : data_in[DW-1:0];
//Byte0
assign byte0_sel[3] = datamode[1:0]==2'b00 & addr[1:0]==2'b11;
assign byte0_sel[2] = datamode[1:0]==2'b00 & addr[1:0]==2'b10 |
datamode[1:0]==2'b01 & addr[1:0]==2'b10;
assign byte0_sel[1] = datamode[1:0]==2'b00 & addr[1:0]==2'b01;
assign byte0_sel[0] = ~(|byte0_sel[3:1]);
//Byte1
assign byte1_sel[1] = (datamode[1:0]==2'b01 & addr[1:0]==2'b00) |
datamode[1:0]==2'b10 |
datamode[1:0]==2'b11;
assign byte1_sel[3] = datamode[1:0]==2'b01 & addr[1:0]==2'b10;
assign byte1_sel[2] = 1'b0;
assign byte1_sel[0] = 1'b0;
//Byte2
assign byte2_sel[2] = datamode[1:0]==2'b10 |
datamode[1:0]==2'b11;
assign byte2_sel[3] = 1'b0;
assign byte2_sel[1] = 1'b0;
assign byte2_sel[0] = 1'b0;
//Byte3
assign byte3_sel[3] = datamode[1:0]==2'b10 |
datamode[1:0]==2'b11;
assign byte3_sel[2] = 1'b0;
assign byte3_sel[1] = 1'b0;
assign byte3_sel[0] = 1'b0;
//Alignment for lower 32 bits(upper 32 bits don't need alignment)
//B0: 32 NANDs,8 NORS
assign data_aligned[7:0] = {(8){byte0_sel[3]}} & data_mux[31:24] |
{(8){byte0_sel[2]}} & data_mux[23:16] |
{(8){byte0_sel[1]}} & data_mux[15:8] |
{(8){byte0_sel[0]}} & data_mux[7:0];
//B1:
assign data_aligned[15:8] = {(8){byte1_sel[3]}} & data_mux[31:24] |
{(8){byte1_sel[1]}} & data_mux[15:8];
//B2: 8 NANDS
assign data_aligned[23:16] = {(8){byte2_sel[2]}} & data_mux[23:16];
//B3:
assign data_aligned[31:24] = {(8){byte3_sel[3]}} & data_mux[31:24];
assign data_out[DW-1:0] = data_aligned[DW-1:0];
endmodule // emesh_rdalign