Procedure of Algorithm for Interfacing ADC:

1. Ensuring stability of analog input:
Before interfacing the Analog-to-Digital Converter (ADC), it is important to ensure the stability of the analog input. This can be achieved by taking the following steps:
- Providing a stable power supply to the analog circuitry.
- Minimizing any noise or interference that may affect the analog input.
- Using proper grounding techniques to reduce the ground loop effect.
- Ensuring that the input signal is within the specified voltage range of the ADC.

2. Issuing start of conversion pulse to ADC:
Once the stability of the analog input is ensured, the next step is to issue the start of conversion pulse to the ADC. This pulse initiates the conversion process where the analog input is sampled and converted into a digital value. The start of conversion pulse can be issued by following these steps:
- Selecting the appropriate control register of the ADC.
- Setting the start of conversion bit in the control register to initiate the conversion process.
- Ensuring that the conversion process is completed before proceeding to the next step.

3. Reading digital data output of ADC as equivalent digital output:
After the conversion process is completed, the ADC generates a digital output that represents the equivalent digital value of the sampled analog input. This digital output can be read by following these steps:
- Accessing the appropriate data register of the ADC.
- Reading the digital value stored in the data register.
- Storing the digital value for further processing or analysis.

4. All of the mentioned:
The correct answer to the question is option 'D' - all of the mentioned. This means that the procedure of the algorithm for interfacing ADC includes ensuring stability of analog input, issuing start of conversion pulse to ADC, and reading the digital data output of the ADC as the equivalent digital output. All these steps are crucial for successfully interfacing an ADC and obtaining accurate digital values from the analog input.

By following this algorithm, the ADC can effectively convert analog signals into digital values, allowing for further processing and analysis in digital systems. It is important to carefully implement each step to ensure accurate and reliable conversion results.