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Diffstat (limited to 'fpga/usrp2/control_lib/ram_harvard.v')
-rw-r--r-- | fpga/usrp2/control_lib/ram_harvard.v | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/fpga/usrp2/control_lib/ram_harvard.v b/fpga/usrp2/control_lib/ram_harvard.v new file mode 100644 index 000000000..00ffb1984 --- /dev/null +++ b/fpga/usrp2/control_lib/ram_harvard.v @@ -0,0 +1,84 @@ +// +// Copyright 2011 Ettus Research LLC +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. +// +// You should have received a copy of the GNU General Public License +// along with this program. If not, see <http://www.gnu.org/licenses/>. +// + + + +// Dual ported, Harvard architecture, cached ram + +module ram_harvard + #(parameter AWIDTH=15, + parameter RAM_SIZE=16384, + parameter ICWIDTH=6, + parameter DCWIDTH=6) + + (input wb_clk_i, + input wb_rst_i, + // Firmware download port. + input [AWIDTH-1:0] ram_loader_adr_i, + input [31:0] ram_loader_dat_i, + input [3:0] ram_loader_sel_i, + input ram_loader_stb_i, + input ram_loader_we_i, + input ram_loader_done_i, + // Instruction fetch port. + input [AWIDTH-1:0] if_adr, + output [31:0] if_data, + // Data access port. + input [AWIDTH-1:0] dwb_adr_i, + input [31:0] dwb_dat_i, + output [31:0] dwb_dat_o, + input dwb_we_i, + output dwb_ack_o, + input dwb_stb_i, + input [3:0] dwb_sel_i ); + + reg ack_d1; + reg stb_d1; + + dpram32 #(.AWIDTH(AWIDTH),.RAM_SIZE(RAM_SIZE)) + sys_ram + (.clk(wb_clk_i), + .adr1_i(ram_loader_done_i ? if_adr : ram_loader_adr_i), + .dat1_i(ram_loader_dat_i), + .dat1_o(if_data), + .we1_i(ram_loader_done_i ? 1'b0 : ram_loader_we_i), + .en1_i(ram_loader_done_i ? 1'b1 : ram_loader_stb_i), + //.sel1_i(ram_loader_done_i ? 4'hF : ram_loader_sel_i), + .sel1_i(ram_loader_sel_i), // Sel is only for writes anyway + .adr2_i(dwb_adr_i), + .dat2_i(dwb_dat_i), + .dat2_o(dwb_dat_o), + .we2_i(dwb_we_i), + .en2_i(dwb_stb_i), + .sel2_i(dwb_sel_i) + ); + + assign dwb_ack_o = dwb_stb_i & (dwb_we_i | (stb_d1 & ~ack_d1)); + + always @(posedge wb_clk_i) + if(wb_rst_i) + ack_d1 <= 1'b0; + else + ack_d1 <= dwb_ack_o; + + always @(posedge wb_clk_i) + if(wb_rst_i) + stb_d1 <= 0; + else + stb_d1 <= dwb_stb_i; + +endmodule // ram_harvard |