To convert Boolean equations to Standard Sum-of-Products (SOP) form and implement them using NAND-NAND logic, follow these steps:
### (I) Y = A'B'C' + ABC'D' + A'C'D'
#### 1. Standard SOP Form
The given Boolean equation is already in SOP form, where each term is a product (AND operation) of literals, and these products are summed (OR operation). To ensure it's in standard SOP form, each product term should include all variables in the expression.
Here, the equation is:
\[ Y = A'B'C' + ABC'D' + A'C'D' \]
We need to include all variables (A, B, C, D) in each term, so we use the following steps:
1. **Expand the Terms:**
- \( A'B'C' \) can be expanded to \( A'B'C'D + A'B'C'D' \) (adding \( D \) and \( D' \)).
- \( ABC'D' \) is already expanded.
- \( A'C'D' \) can be expanded to \( A'C'D' \) (adding \( B \) and \( B' \)).
Combining these, the standard SOP form is:
\[ Y = A'B'C'D + A'B'C'D' + ABC'D' + A'B'C'D' + A'B'C'D + A'B'C'D' \]
After combining like terms:
\[ Y = A'B'C'D + A'B'C'D' + ABC'D' + A'C'D' \]
#### 2. Implementing using NAND-NAND Logic
To implement this using NAND gates, follow these steps:
1. **Convert SOP to NAND-NAND form:**
- First, express the SOP form in terms of NAND gates. For any Boolean equation \( F = \overline{\overline{F}} \), where \( \overline{F} \) is the NAND representation of \( F \).
2. **Construct the NAND equivalent:**
Each AND gate can be implemented using NAND gates by De Morgan's theorem. Similarly, OR gates can be implemented using NAND gates.
For example:
- \( A \cdot B = \overline{ \overline{A \cdot B} } \) can be implemented as \( \overline{\overline{A} \cdot \overline{B}} \).
Convert each product term and OR operation into NAND gates:
- \( A'B'C' = \overline{\overline{A'B'C'}} = \overline{(\overline{A'} + \overline{B'} + \overline{C'})} \)
- \( ABC'D' = \overline{\overline{A \cdot B \cdot C' \cdot D'}} = \overline{\overline{A} + \overline{B} + C + D} \)
- \( A'C'D' = \overline{\overline{A' \cdot C' \cdot D'}} = \overline{A + \overline{C} + \overline{D}} \)
Finally, OR the product terms using NAND gates:
- To OR terms \( T_1, T_2, T_3, \ldots \), use \( \overline{\overline{T_1} \cdot \overline{T_2} \cdot \ldots} \).
### (II) Y = PQ + P'QR + PQR
#### 1. Standard SOP Form
This Boolean equation is also in SOP form. Each term is already a product of literals.
The given equation is:
\[ Y = PQ + P'QR + PQR \]
This is already in standard SOP form.
#### 2. Implementing using NAND-NAND Logic
To implement this using NAND gates:
1. **Convert SOP to NAND-NAND form:**
- Apply De Morgan's theorem to convert AND and OR operations to NAND operations.
Each term:
- \( PQ = \overline{\overline{PQ}} = \overline{\overline{P} + \overline{Q}} \)
- \( P'QR = \overline{\overline{P'QR}} = \overline{P + \overline{Q} + \overline{R}} \)
- \( PQR = \overline{\overline{PQR}} = \overline{\overline{P} + \overline{Q} + \overline{R}} \)
To OR the terms, use:
- \( Y = \overline{\overline{PQ} \cdot \overline{P'QR} \cdot \overline{PQR}} \)
Construct the NAND gates to achieve this.
### Summary
- For \( Y = A'B'C' + ABC'D' + A'C'D' \), convert each product and sum to NAND gates.
- For \( Y = PQ + P'QR + PQR \), express each term in NAND and then combine them.
Both tasks involve expressing the given Boolean functions using NAND gates by applying De Morgan's laws to convert AND and OR operations into NAND operations.