upsilon/gateware/rtl/control_loop/adc_sim.v

83 lines
1.5 KiB
Verilog

/* Copyright 2023 (C) Peter McGoron
* This file is a part of Upsilon, a free and open source software project.
* For license terms, refer to the files in `doc/copying` in the Upsilon
* source distribution.
*/
module adc_sim #(
parameter POLARITY = 1,
parameter PHASE = 0,
parameter WID = 18,
parameter WID_LEN = 5
) (
input clk,
input [WID-1:0] indat,
input rst_L,
output reg request,
input fulfilled,
output err,
output miso,
input sck,
input ss_L
);
wire ss = !ss_L;
reg ss_raised = 0;
reg fulfilled_raised = 0;
reg ss_buf_L = 1;
reg [WID-1:0] data = 0;
reg rdy = 0;
wire spi_fin;
always @ (posedge clk) begin
if (!rst_L) begin
ss_raised <= 0;
fulfilled_raised <= 0;
ss_buf_L <= 1;
data <= 0;
rdy <= 0;
request <= 0;
end else if (ss && !ss_raised) begin
request <= 1;
ss_raised <= 1;
end else if (ss_raised && !ss) begin
ss_raised <= 0;
ss_buf_L <= 1;
rdy <= 0;
request <= 0;
fulfilled_raised <= 0;
end else if (ss_raised && request && fulfilled && !fulfilled_raised) begin
data <= indat;
fulfilled_raised <= 1;
request <= 0;
rdy <= 1;
end else if (ss_raised && !fulfilled && fulfilled_raised) begin
fulfilled_raised <= 0;
ss_buf_L <= 0;
end else if (spi_fin) begin
rdy <= 0;
end
end
spi_slave_no_read #(
.WID(WID),
.WID_LEN(WID_LEN),
.POLARITY(POLARITY),
.PHASE(PHASE)
) spi (
.clk(clk),
.sck(sck),
.rst_L(rst_L),
.ss_L(ss_buf_L),
.miso(miso),
.to_master(data),
.finished(spi_fin),
.rdy(rdy),
.err(err)
);
endmodule
`undefineall