Light-weight on-chip signal monitor with integrated memory management and data collection

An on-chip signal monitor comprising:

• a clock and data recovery (CDR) unit that provides a reference clock signal;
• a state machine that includes a sequencing logic, the sequencing logic configured to initiate each sample acquisition and to trigger an update of a digitized time value;
• at least one flip flop connected to the CDR unit and the sequencing logic, the at least one flip flop configured to pass a rising edge of the reference clock signal from the CDR unit to an input of a programmable delay chain responsive to a sample gate signal from the sequencing logic;
• the programmable delay chain that receives the digitized time value and outputs a delayed rising edge of the reference clock signal to a sample-and-hold circuit at a time slice window determined by the digitized time value;
• a sample capture unit that includes:
• the sample-and-hold circuit that captures and integrates an input signal over the time slice window to output an average voltage of the input signal responsive to the delayed rising edge;
• and
• an analog-to-digital converter (ADC) that receives the average voltage of the input signal at the time slice window and digitizes the average voltage of the input signal to a digitized amplitude value;
• an address generator that uses the digitized time value and the digitized amplitude value to form an address of an accumulator register located in a memory;
• and
• a load-increment-store logic that fetches a value of the accumulator register from the address of the memory, increments the value by 1, and stores the incremented value in the address.

A method of acquiring samples using an automatic signal monitor, the method comprising:

• setting a sample gate signal to initiate sample acquisition;
• capturing an input signal over a time slice window to output an average voltage of the input signal in the time slice window, wherein the time slice window is determined by a digitized time value stored in a counter;
• digitizing the average voltage of the input signal to a digitized amplitude value;
• forming an address of a memory based on the digitized time value and the digitized amplitude value;
• and
• incrementing a value stored at the address in the memory by 1.

A method of acquiring samples using an automatic signal monitor, the method comprising:

• setting a sample gate signal to initiate sample acquisition;
• capturing a sample within a time slice window determined by a digitized time value and an amplitude slice window determined by a digitized amplitude value, wherein the digitized time value and the digitized amplitude value are stored in a counter;
• generating a sample-in-window signal with a trigger level to trigger an update of a value at an address in a memory, the address determined by the digitized time value and the digitized amplitude value;
• forming the address of the memory based on the digitized time value and the digitized amplitude value;
• and
• incrementing the value stored at the address in the memory by 1.