
3-33
IM 701450-51E
SPI Bus Signal Analysis Function
3
• When the CS Signal Is ON
The data containing the reference point becomes analysis number 0. However, if the
reference point is between two data points, the first detected data after the reference
point becomes analysis number 0.
Reference point
No.-1
1
2
3
4
5
6
7
8
Data
Clock
No.0
1
2
3
4
5
6
7
8
Reference point
No.0
1
2
3
4
5
6
7
8
Data
Clock
No.1
1
2
3
4
5
6
7
8
CS
CS
Note
If you set the reference point to Trigger Position, the data containing the trigger point is
analysis number 0. However, if a trigger is activated on the trigger conditions of the SPI Bus
signal, the trigger point is the data boundary. Hence, the analysis number of the data on
which the trigger is activated is 0 or –1.
Data1 and Data2 Values
The Data1 and Data2 values are displayed in hexadecimal. However, below are some
exceptions.
• When the data is less than 8 bits, “–” is displayed.
• When indefinite data (bit whose status is neither 1 or 0) exists, “
∗
” is displayed.
Indefinite data is considered the same status as the previous bit for the analysis. If
the first bit (left most bit in the display range) is indefinite data, it is analyzed as 0.
CS
Displays the CS signal enable status. Note the following:
• When none of the CS signal is ON, blank is displayed.
• When only one CS signal is ON, the status H or L of the CS signal is displayed.
• When multiple CS signals are ON, the name of the CS signal with high priority is
displayed. For a description of the priority, see page “Priority” on page 3-31.
Display Example of Analysis Data
Examples of analysis using different analysis conditions are indicated below.
Clock
Data1
Data2
CS
Reference point
0
0
0
0
1
0
0
0
1
1
0
1
1
0
0
0
1
1
1
0
0
1
0
0
0
0
1
1
1
1
0
1
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Bit order: MSB First
3.5 Analyzing/Searching Data