Tektronix DPO2304SX, Printable Help

Page: 701 / 920

Bus trigger
A bus trigger occurs when a supported instrument detects a bus pattern that you specify for a parallel bus, or a bus cycle you
select for aserial bus.
You can set the instrument to trigger on a parallel bus when the instrument detects a match to the bus pattern, or when the
instrument detects that the value on the bus is < or > the value of the bus pattern. The pattern can be in Binary, Hex, or Symbolic
format.
You can set the instrument to trigger on an SPI bus when the instrument detects an SS or an MISO + MOSI bus cycle. For the
MISO + MOSI selection, click the Edit button to define the Data Value pattern, and then set the Format to match.
You can set the instrument to trigger on an I2C bus when the instrument detects a Start, Stop, Repeated Start, Missing Ack,
Address, Data, or Addr + Data bus cycle or activity. For some Trigger On selections, you need to set additional fields to define
other parameters, such as for an Address. In this example, you need to set an Address Format, Address Value (click the Edit
button), Data Direction, and Addressing Mode.
You can set the instrument to trigger on a USB bus when the instrument detects a Sync, Reset, Suspend, Resume, End of
Packet, Token (Address) Packet, Data Packet, Handshake Packet, Handshake Packet, Special Packet, or Error bus cycle or
activity. For some Trigger On selections, you need to set additional fields to define other parameters, such as for a Token
(Address) Packet. In this example, you need to set a Token Type, Trigger when address is, Address Format, Address (click the
Edit button), and when endpoint is equal to Endpoint Format, and Endpoint.
You can set the instrument to trigger on an RS232 bus when the instrument detects a Start, End of Packet, Data, or Parity Error
bus cycle or activity. For some Trigger On selections, you need to set additional fields to define other parameters, such as for a
Data. In this example, you need to set a Data Format, Number of Bytes, and Data Value (click the Edit button).
You can set the instrument to trigger on an 8b10b bus when the instrument detects a Pattern, Character/Symbol, Error, or Any
Control Character. For some Trigger On selections, you need to set additional fields to define other parameters, such as for a
Pattern.
For all the serial standard buses, you can also set the component threshold levels through the Logic Thresholds Setup button.
Communication trigger
Use the Comm trigger to trigger the instrument in conjunction with mask testing on communications codes and standards. The
controls work together to define the parameters for the trigger event. Comm triggers are not available on DPO70000SX
instruments.
The standards that appear in the Standard drop-down list depend on the coding format that you selected. The coding format also
determines whether upper, lower, single, or clock threshold levels or pulse forms are used. The standard determines the bit rate.
Communication triggering
Communication (Comm) triggers are one type of trigger. Comm triggers are designed to work with communication masks and
standards. When you select a mask to test, it is associated with a specific communication standard. The mask you select
determines the Comm trigger needed for that standard. Comm triggers are not available on DPO70000SX instruments.
NOTE. The Comm Trigger is designed to work with communications mask and standard testing. Mask testing automatically uses
Communication triggers. You must install the
Serial Communications Mask Testing Option on some instruments before you can
access the Comm triggers.
Eye diagrams that are set up with an external clock use a time base position value large enough to guarantee the edge is always
before the acquisition record starts. This forces all Comm triggers to disable the B-Trigger.
Even though Comm triggers are designed to work with masks, you can set up Comm triggering without using a mask. You can
also set up your own mask to use with Comm triggers.
What do you want to do next?
Learn about mask testing.
Oscilloscope reference
DPO70000SX, MSO/DPO70000DX, MSO/DPO70000C, DPO7000C, and MSO/DPO5000B Series 669