blob: 2f3fc2ad4d80b83a5060f7fc0697f44f9102ab27 [file] [log] [blame]
`default_nettype none
// Digital PLL (ring oscillator + controller)
// Technically this is a frequency locked loop, not a phase locked loop.
`include "digital_pll_controller.v"
`include "ring_osc2x13.v"
module digital_pll(
resetb, enable, osc, clockp, div, dco, ext_trim);
input vdd;
input vss;
input resetb; // Sense negative reset
input enable; // Enable PLL
input osc; // Input oscillator to match
input [4:0] div; // PLL feedback division ratio
input dco; // Run in DCO mode
input [25:0] ext_trim; // External trim for DCO mode
output [1:0] clockp; // Two 90 degree clock phases
wire [25:0] itrim; // Internally generated trim bits
wire [25:0] otrim; // Trim bits applied to the ring oscillator
wire creset; // Controller reset
wire ireset; // Internal reset (external reset OR disable)
assign ireset = ~resetb | ~enable;
// In DCO mode: Hold controller in reset and apply external trim value
assign itrim = (dco == 1'b0) ? otrim : ext_trim;
assign creset = (dco == 1'b0) ? ireset : 1'b1;
ring_osc2x13 ringosc (
digital_pll_controller pll_control (
`default_nettype wire