module omsp_dbg_uart (dbg_clk, dbg_rst, mem_burst, cmd_valid); input dbg_clk; input dbg_rst; input mem_burst; output cmd_valid; reg [2:0] uart_state; reg [2:0] uart_state_nxt; wire xfer_done; parameter RX_SYNC = 3'h0; parameter RX_CMD = 3'h1; parameter RX_DATA = 3'h2; always @(uart_state or mem_burst) case (uart_state) RX_SYNC : uart_state_nxt = RX_CMD; RX_CMD : uart_state_nxt = mem_burst ? RX_DATA : RX_SYNC; RX_DATA : uart_state_nxt = RX_SYNC; default : uart_state_nxt = RX_CMD; endcase always @(posedge dbg_clk or posedge dbg_rst) if (dbg_rst) uart_state <= RX_SYNC; else if (xfer_done | mem_burst) uart_state <= uart_state_nxt; assign cmd_valid = (uart_state==RX_CMD) & xfer_done; assign xfer_done = uart_state!=RX_SYNC; endmodule