Remora - Rpi Software Stepping Using External Microcontroller via SPI

module stepgen     (         input clk,         input signed [31:0] jointFreqCmd,         output signed [31:0] jointFeedback,         output DIR,         output STP     );     assign DIR = (jointFreqCmd > 0);     reg [31:0] jointCounter = 32'd0;     reg [31:0] jointFreqCmdAbs = 32'd0;     reg signed [31:0] jointFeedbackMem = 32'd0;     reg step = 0;     assign STP = step;     assign jointFeedback = jointFeedbackMem;     always @ (posedge clk) begin         if (DIR) begin             jointFreqCmdAbs = jointFreqCmd / 2;         end else begin             jointFreqCmdAbs = -jointFreqCmd / 2;         end         jointCounter <= jointCounter + 1;         if (jointFreqCmd != 0) begin             if (jointCounter >= jointFreqCmdAbs) begin                 step <= ~step;                 jointCounter <= 32'b0;                 if (step) begin                     if (DIR) begin                         jointFeedbackMem = jointFeedbackMem + 1;                     end else begin                         jointFeedbackMem = jointFeedbackMem - 1;                     end                 end             end         end     end endmodule