3-11
IM 701450-51E
SPI Bus Signal Analysis Function
3
Explanation
Setting the Trigger Conditions of the SPI Bus Signal: SPI Setup
You can set the following conditions.
Pattern Format
Select the format for Pattern A and Pattern B from the following:
Hex
Hexadecimal
Bin
Binary
Bit Order
You can select the bit order of Pattern A and Pattern B according to the signal flow of the
input/output data. When setting the pattern in binary, set the data in the order of the flow
regardless of the bit order setting. When setting the pattern in hexadecimal, enter the
pattern according to the bit order setting, separated every four bits in the order of the
flow.
MSB First
Select this when the I/O data signal is flowing MSB first.
LSB First
Select this when the I/O data signal is flowing LSB first.
Note
The bit order setting is connected with the setting in the Analyze Setup dialog box (see page
3-26).
Type of the SPI Bus Signal Trigger Condition
You can select the type of the SPI Bus signal trigger condition from the four types listed
below. You can use the AND condition to select multiple types at the same time.
However, Assertion of SS and Byte Count are always selected.
• Assertion of SS(CH4)
The trigger function of the SPI Bus signal counts the valid edges of SCK (CH1) after
SS (CH4) is asserted and divides MOSI (CH2) or MISO (CH3) into bytes. Therefore,
Assertion of SS (CH4) is always selected.
• A Pattern
Set the bit pattern used to compare with the command or address sent from the
master to the slave. The pattern is compared with the bit pattern of MOSI (CH2) that
is present immediately after SS (CH4) is asserted.
• Byte Count
You can activate a trigger after the specified number of bytes elapses after the
assertion of SS (CH4) (after the condition of Pattern A is met when Pattern A is
selected). You can set the byte count in the range of 0 to 1000. The Byte Count item
is always selected. If you do not wish to use Byte Count as a trigger condition, set the
value to 0.
• B Pattern
Set the bit pattern used to compare with the data written by the master to the slave or
the data read by the master from the slave. You can select write data (MOSI) or read
data (MISO) to be compared. The pattern is compared with the bit pattern the byte
count after the assertion of SS (CH4).
Note
If multiple types are combined, the trigger point is set to the trigger point of the type that
appeared last in the time sequence.
3.4 Setting SPI Bus Signal Acquisition Conditions
