Altera RapidIO II MegaCore Function - Manual (Page 200)

7–6 Chapter 7: Testbench
Testbench Sequence
RapidIO II MegaCore Function August 2014 Altera Corporation
User Guide
SWRITE Transactions
The next set of operations performed are Streaming Writes (SWRITE). To perform
SWRITE
operations, one register in the IP core must be reconfigured as shown in
Table 7–2 .
With the setting in Table 7–2 , any write operation presented across the Input/Output
Avalon-MM slave interface on the rio module is translated to a RapidIO Streaming
Write transaction.
1 The Avalon-MM write address must map into Input/Output Slave Window 0.
However, in this example the window is set to cover the entire Avalon-MM address
space by setting the mask to all zeros.
The testbench generates a predetermined series of burst writes across the Avalon-MM
slave I/O interface on the DUT. These write bursts are each converted to an SWRITE
request packet sent on the RapidIO serial interface. Because Streaming Writes only
support bursts that are multiples of a double word (multiple of 8 bytes), the testbench
cycles from 8 to MAX_WRITTEN_BYTES in steps of 8 bytes. The
ios_128_rd_wr_master_bfm read_write_cmd task generates and checks the streaming
write transaction.
At the sister_rio module, the SWRITE request packets are received and translated into
Avalon-MM transactions that are presented across the Input/Output master
Avalon-MM interface. The testbench calls the task read_write_data of the
sister_iom128_rd_wr_slave_bfm to capture the written data.
The written data is then checked against the expected value by running an expect_1
task. After completing the SWRITE tests, the testbench performs NREAD operations.
NREAD Transactions
The next set of transactions tested are NREADs. The DUT sends a group of NREAD
transactions to the sister_rio module by cycling the read burst size from four to five in
increments of 16 bytes. For each iteration, the ios_128_rd_wr_master_bfm
read_write_cmd
and read_data tasks are called. The task performs the read request
packets across the I/O Avalon-MM Slave Read interface. The read transaction across
the Avalon-MM interface is translated into a RapidIO NREAD request packets.
Table 7–2. SWRITE Register
Module
Register
Address
Name Value Description
rio 0x1040C
Input/Output
Slave Mapping
Window 0 Control
32'h00CD_0002 or
32'hCDCD_0002
Sets the DESTINATION_ID for outgoing transactions
to the value 0xCD or 0xCDCD, depending on the
device ID width of the sister_rio. This value matches
the base device ID of the sister_rio module. Enables
SWRITE
operations.