Instructions

Protocol Analysis
R&S
®
Scope Rider RTH
192User Manual 1326.1578.02 ─ 15
The Serial Peripheral Interface SPI is used for communication with slow peripheral
devices, in particular, for transmission of data streams.
Main characteristics of SPI are:
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Master-slave communication
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No device addressing; The slave is accessed by a chip select, or slave select line.
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No acknowledgement mechanism to confirm receipt of data
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Duplex capability
Most SPI buses have four lines, two data and two control lines:
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Clock line to all slaves (SCLK)
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Slave Select or Chip Select line (SS or CS)
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Master data output, slave data input (MOSI or SDI)
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Master data input, slave data output (MISO or SDO)
When the master generates a clock and selects a slave device, data may be transfer-
red in either or both directions simultaneously.
Figure 9-15: Simple configuration of SPI bus
The data bits of a message are grouped by following criteria:
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A word contains a number of successive bits. The word length is defined in the pro-
tocol configuration.
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A frame contains a number of successive words, at least one word.
For SPI buses, the R&S RTH provides the following trigger possibilities:
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On frame start
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On frame end
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On a serial pattern at a specified position
9.3.2 SPI Configuration Settings
Access: "Bus" menu > "Bus Protocol" = "SPI" > "Config"
SPI (Option R&S RTH-K1)