| Line 55... |
Line 55... |
if ((i_stb)&&(cmd_write_not_compressed))
|
if ((i_stb)&&(cmd_write_not_compressed))
|
wr_addr <= wr_addr + 8'h1;
|
wr_addr <= wr_addr + 8'h1;
|
|
|
reg [31:0] compression_tbl [0:255];
|
reg [31:0] compression_tbl [0:255];
|
always @(posedge i_clk)
|
always @(posedge i_clk)
|
|
if (i_stb)
|
compression_tbl[wr_addr] <= { i_word[32:31], i_word[29:0] };
|
compression_tbl[wr_addr] <= { i_word[32:31], i_word[29:0] };
|
|
|
reg [35:0] r_word;
|
reg [35:0] r_word;
|
always @(posedge i_clk)
|
always @(posedge i_clk)
|
|
if (i_stb)
|
r_word <= i_word;
|
r_word <= i_word;
|
|
|
|
|
// Clock two, calculate the table address ... 1 is the smallest address
|
// Clock two, calculate the table address ... 1 is the smallest address
|
// { o_stb, r_stb } = 4'h2 when done
|
// { o_stb, r_stb } = 4'h2 when done
|
| Line 125... |
Line 127... |
// thus ... things will hold still for much longer than just 5 clocks.
|
// thus ... things will hold still for much longer than just 5 clocks.
|
always @(posedge i_clk)
|
always @(posedge i_clk)
|
if (r_word[35:30] == 6'b101110)
|
if (r_word[35:30] == 6'b101110)
|
o_word <= r_word;
|
o_word <= r_word;
|
else casez(r_word[35:30])
|
else casez(r_word[35:30])
|
|
// Set address from something compressed ... unsigned
|
6'b001??0: o_word <= { 4'h0, w_addr[31:0] };
|
6'b001??0: o_word <= { 4'h0, w_addr[31:0] };
|
|
// Set a new address as a signed offset from the last (set) one
|
|
// (The last address is kept further down the chain,
|
|
// we just mark here that the address is to be set
|
|
// relative to it, and by how much.)
|
6'b001??1: o_word <= { 3'h1, w_addr[31:30], 1'b1, w_addr[29:0] };
|
6'b001??1: o_word <= { 3'h1, w_addr[31:30], 1'b1, w_addr[29:0] };
|
|
// Write a value to the bus, with the value given from our
|
|
// codeword table
|
6'b010???: o_word <=
|
6'b010???: o_word <=
|
{ 3'h3, cword[31:30], r_word[30], cword[29:0] };
|
{ 3'h3, cword[31:30], r_word[30], cword[29:0] };
|
6'b10????: o_word <= { 5'b11000, r_word[30],
|
// Read, highly compressed length (1 word)
|
20'h00, rd_len };
|
6'b10????: o_word <= { 5'b11000, r_word[30], 20'h00, rd_len };
|
6'b11????: o_word <= { 5'b11000, r_word[30],
|
// Read, two word (3+9 bits) length
|
20'h00, rd_len };
|
6'b11????: o_word <= { 5'b11000, r_word[30], 20'h00, rd_len };
|
default: o_word <= r_word;
|
default: o_word <= r_word;
|
endcase
|
endcase
|
endmodule
|
endmodule
|
|
|
|
|
No newline at end of file
|
No newline at end of file
|
