Design for testability (DFT) in PCB Design - Cell-by-Cell Formula Trace

Sample Data

This data shows PCB components with their number of test points and test coverage percentage.

Cell	Value
A1	Component
B1	Test Points
C1	Test Coverage (%)
A2	Resistor R1
B2	2
C2	80
A3	Capacitor C1
B3	1
C3	60
A4	IC U1
B4	5
C4	95
A5	Connector J1
B5	3
C5	85

Formula Trace

=SUM(B2:B5)

Step 1: B2

Step 2: B3

Step 3: B4

Step 4: B5

Step 5: SUM(2, 1, 5, 3)

Cell Reference Map

    A          B          C
1 Component  Test Points Test Coverage
2 Resistor R1  --> 2       80
3 Capacitor C1 --> 1       60
4 IC U1       --> 5       95
5 Connector J1-> 3       85

Cells B2 to B5 are referenced to sum the total test points on the PCB.

Result

    A          B          C
1 Component  Test Points Test Coverage
2 Resistor R1  2          80
3 Capacitor C1 1          60
4 IC U1       5          95
5 Connector J1 3          85
6 Total Test Points: 11

The formula sums test points from B2 to B5, resulting in 11 total test points for the PCB design.

Sheet Trace Quiz - 3 Questions

What is the value in cell B4?

A 3

B 5

C 1

D 2

Key Result

SUM(range) adds all numeric values in the specified cell range.