diff options
Diffstat (limited to 'fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v')
| -rw-r--r-- | fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v | 108 |
1 files changed, 60 insertions, 48 deletions
diff --git a/fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v b/fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v index 6cd45b86b..3747481ed 100644 --- a/fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v +++ b/fpga/usrp3/lib/rfnoc/utils/ctrlport_clk_cross.v @@ -11,9 +11,7 @@ // -module ctrlport_clk_cross #( - parameter DEVICE = "7SERIES" // FPGA technology identifier (for optimal FIFO inference) -)( +module ctrlport_clk_cross ( input wire rst, // Can be either clock domain, but must be glitch-free //--------------------------------------------------------------------------- @@ -54,6 +52,16 @@ module ctrlport_clk_cross #( input wire [ 1:0] m_ctrlport_resp_status, input wire [31:0] m_ctrlport_resp_data ); + //--------------------------------------------------------------------------- + // Reset sync to both clock domains + //--------------------------------------------------------------------------- + wire m_rst, s_rst; + reset_sync master_reset_sync_inst ( + .clk(m_ctrlport_clk), .reset_in(rst), .reset_out(m_rst) + ); + reset_sync slave_reset_sync_inst ( + .clk(s_ctrlport_clk), .reset_in(rst), .reset_out(s_rst) + ); //--------------------------------------------------------------------------- // Slave to Master Clock Crossing (Request) @@ -77,52 +85,53 @@ module ctrlport_clk_cross #( wire m_ctrlport_req_wr_tmp; wire m_ctrlport_req_rd_tmp; - // Sort by descreasing order of usage possibility. - // This way instance, which do not need port IDs, time etc. can save the MSBs. assign s_req_flat = { + s_ctrlport_req_wr, + s_ctrlport_req_rd, + s_ctrlport_req_addr, s_ctrlport_req_portid, s_ctrlport_req_rem_epid, s_ctrlport_req_rem_portid, - s_ctrlport_req_has_time, - s_ctrlport_req_time, - s_ctrlport_req_byte_en, s_ctrlport_req_data, - s_ctrlport_req_addr, - s_ctrlport_req_wr, - s_ctrlport_req_rd + s_ctrlport_req_byte_en, + s_ctrlport_req_has_time, + s_ctrlport_req_time }; - axi_fifo_2clk #( - .WIDTH (REQ_W), - .SIZE (3), - .DEVICE (DEVICE) - ) req_fifo ( - .reset (rst), - .i_aclk (s_ctrlport_clk), - .i_tdata (s_req_flat), - .i_tvalid (s_ctrlport_req_wr | s_ctrlport_req_rd), - .i_tready (), - .o_aclk (m_ctrlport_clk), - .o_tdata (m_req_flat), - .o_tready (1'b1), - .o_tvalid (m_req_flat_valid) + // Busy flag can be ignored as the response handshake takes at least the same + // amount of cycles to transfer the response as this handshake instance needs + // to release the busy flag as they are configured with the same amount of + // synchronization stages. Furthermore the ctrlport protocol just allows for + // one transaction to be active at the same time. A request can only be issued + // once the response is provided. + handshake #( + .WIDTH(REQ_W) + ) req_handshake_inst ( + .clk_a(s_ctrlport_clk), + .rst_a(s_rst), + .valid_a((s_ctrlport_req_wr | s_ctrlport_req_rd) & ~s_rst), + .data_a(s_req_flat), + .busy_a(), + .clk_b(m_ctrlport_clk), + .valid_b(m_req_flat_valid), + .data_b(m_req_flat) ); assign { + m_ctrlport_req_wr_tmp, + m_ctrlport_req_rd_tmp, + m_ctrlport_req_addr, m_ctrlport_req_portid, m_ctrlport_req_rem_epid, m_ctrlport_req_rem_portid, - m_ctrlport_req_has_time, - m_ctrlport_req_time, - m_ctrlport_req_byte_en, m_ctrlport_req_data, - m_ctrlport_req_addr, - m_ctrlport_req_wr_tmp, - m_ctrlport_req_rd_tmp + m_ctrlport_req_byte_en, + m_ctrlport_req_has_time, + m_ctrlport_req_time } = m_req_flat; - assign m_ctrlport_req_wr = m_ctrlport_req_wr_tmp & m_req_flat_valid; - assign m_ctrlport_req_rd = m_ctrlport_req_rd_tmp & m_req_flat_valid; + assign m_ctrlport_req_wr = m_ctrlport_req_wr_tmp & m_req_flat_valid & ~m_rst; + assign m_ctrlport_req_rd = m_ctrlport_req_rd_tmp & m_req_flat_valid & ~m_rst; //--------------------------------------------------------------------------- @@ -145,20 +154,23 @@ module ctrlport_clk_cross #( m_ctrlport_resp_data }; - axi_fifo_2clk #( - .WIDTH (RESP_W), - .SIZE (3), - .DEVICE (DEVICE) - ) resp_fifo ( - .reset (rst), - .i_aclk (m_ctrlport_clk), - .i_tdata (m_resp_flat), - .i_tvalid (m_ctrlport_resp_ack), - .i_tready (), - .o_aclk (s_ctrlport_clk), - .o_tdata (s_resp_flat), - .o_tready (1'b1), - .o_tvalid (s_resp_flat_valid) + // Busy flag can be ignored as the request handshake takes at least the same + // amount of cycles to transfer the request as this handshake instance needs + // to release the busy flag as they are configured with the same amount of + // synchronization stages. Furthermore the ctrlport protocol just allows for + // one transaction to be active at the same time. A response can only be + // issued once the request is available. + handshake #( + .WIDTH(RESP_W) + ) resp_handshake_inst ( + .clk_a(m_ctrlport_clk), + .rst_a(m_rst), + .valid_a(m_ctrlport_resp_ack & ~m_rst), + .data_a(m_resp_flat), + .busy_a(), + .clk_b(s_ctrlport_clk), + .valid_b(s_resp_flat_valid), + .data_b(s_resp_flat) ); assign { @@ -167,6 +179,6 @@ module ctrlport_clk_cross #( s_ctrlport_resp_data } = s_resp_flat; - assign s_ctrlport_resp_ack = s_ctrlport_resp_ack_tmp & s_resp_flat_valid; + assign s_ctrlport_resp_ack = s_ctrlport_resp_ack_tmp & s_resp_flat_valid & ~s_rst; endmodule |