User manual

38 www.xilinx.com SPI-4.2 v8.5 Getting Started Guide
UG154 March 24, 2008
Chapter 4: Detailed Example Design
R
Procedures Module
The procedures module is a package of functions instantiated in the testcase module to
simplify sending data and status to the stimulus module. Using these functions, you can
create any desired sequence of data or status. The method by which functions are called
varies among languages, and is described in the appendices.
The following functions are supported in the procedures module:
• send_packet Used to transmit an entire packet of data. This procedure will always
send an SOP control word before the burst of data and an EOP control word following
the data burst.
• send_user_data Used to transmit a burst of data. The presence of an SOP control
word (before the burst of data) and an EOP control word (following the data burst)
can be specified. The EOP can optionally specify an abort (ERR).
• send_idles Used to send idle cycles.
• send_training Used to send training patterns.
• sop_spacing Used to send erred data by sending two SOP words in less than eight
cycles. This function limits the number of cycles between the two SOPs to less than
seven. This ensures that an SOP spacing error occurs.
• reset Used to reset the interface to the stimulus module. Should be called at the
beginning of any testcase.
• send_status Used to change the status (on TStat) for a particular channel.
• get_status Used to check the status of a specific channel.
Data Monitor
The data monitor is responsible for verifying that data sent from the demonstration test
bench is the same as the data received from the core. This is accomplished by monitoring
the
RDat and RCtl signals that are input into the Sink core, and comparing them to the
TCtl and TDat signals output from the Source core. This is a simple comparison as long as
the data being sent does not violate the OIF-SPI4-02.1 specification. If the specification is
violated, the SPI-4.2 core modifies the data to enforce compliance, and the data monitor
accounts for the modification before comparing TDat to RDat. In addition to the data, the
monitor also verifies DIP4, SOP spacing, IDLE request, Training request, DATA_MAX_T,
and ALPHA_DATA compliance. Changes in the testcase can create situations that cause the
data monitor to output warning messages. For more information on output warning
messages, see Appendix C, “Data and Status Monitor Warnings.”
Status Monitor
The status monitor inspects the RStat bus. In addition to verifying correct values for
channel status, it compiles the current status for each channel into the vector FullVec.
FullVec is used by the testcase module when the CHECK_RSTAT constant is set to stall
data on RDat when the targeted channel is full. See Table 4-11 for more information about
the FullVec vector.
The status monitor also calculates the DIP2 value for RStat and compares it with what is
actually received. If there is an error, it looks at the signal SnkDIP2ErrRequest to see if it
was asserted and the error is expected.