GPS GPS-1000X Series, Руководство пользователя

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88 User Manual
SPI Triggering
After the oscilloscope has been set up to capture SPI signals, you can then trigger on a
data pattern that occurs at the start of a frame. The serial data string can be specified to
be from 4 to 96 bits long.
1. Press Setup button on the front panel to enter the TRIGGER function menu.
2. Press the Type softkey; then, turn the Universal Knob to select the serial slot ( Serial
1 or Serial 2 ) on which the SPI signals are being decoded above.
3. Press the Trigger Setting softkey to enter the SPI TRIG SET menu.
Figure 43 SPI TRIG SET Menu
4. Press the Trigger Type softkey to select the trigger condition.

MISO DATA (Master-In, Slave-Out) — for triggering on the MISO data signal.
 MOSI DATA (Master-Out, Slave-In) — for triggering on the MOSI data signal.
5. Press the Data Length softkey, and turn the Universal Knob to set the number of bits
in the serial data string. The number of bits in the string can be set anywhere from 4
bits to 96 bits. The data values for the serial string are displayed in the MISO/ MOSI
data string in the waveform area.
6. For each bit in the MISO/ MOSI data string:
a. Press the Bit Roll softkey; then, turn the Universal Knob to select the bit location.
As you rotate the Entry knob, the bit is highlighted in the Data string shown in the
waveform area.
b. Press the Bit Value softkey to set the bit selected in the Bit Roll softkey to 0 (low),
1 (high), or X (don't care).
7. Press the All Same softkey will set all bits in the data string to 0 (low), 1 (high), or X
(don't care) at once.
8. Press the Bit Order softkey to set the bit order to LSB (Least significant bit first) or
MSB (Most significant bit first) which used when displaying data in the serial decode
waveform and in the Lister.
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