Altera RapidIO MegaCore Function - Manual (Page 169)

Chapter 7: Testbenches 7–7
August 2014 Altera Corporation RapidIO MegaCore Function
User Guide
Initially, the testbench performs two single word transfers, writing to an even word
address first and then to an odd word address. The testbench then generates a
predetermined series of burst writes across the Input/Output Avalon-MM slave
module's Avalon-MM write interface on the DUT. These write bursts are each
converted into NWRITE_R request packets sent over the RapidIO Serial interface. The
testbench cycles from 8 to MAX_WRITTEN_BYTES in steps of 8 bytes. Two tasks are
invoked to carry out the burst writes, rw_addr_data and rw_data. The rw_addr_data
task initiates the burst and the rw_data task completes the burst.
At the sister_rio module, the NWRITE_R request packets are received and presented
across the I/O master Avalon-MM interface as write transactions. The testbench calls
the read_writedata task of the sister_bfm_io_write_slave module. The task captures
the written data. The written data is checked against the expected value.
In addition, the test checks that the NWRITE_RS_COMPLETED interrupt field of the
Input/Output Slave Interrupt
register is set, then clears the field, and checks again
to confirm the field was cleared correctly.
NWRITE Transactions
To perform NWRITE operations, one register in the IP core must be reconfigured as
shown in
Table 7–4 . With these settings, any write operation presented across the
Input/Output Avalon-MM slave interface is translated into a RapidIO NWRITE
transaction.
Initially, the testbench performs two single word transfers, writing to an even word
address first and then to an odd word address. The testbench then generates a
predetermined series of burst writes across the Input/Output Avalon-MM slave
module's Avalon-MM write interface on the DUT. These write bursts are each
converted into an NWRITE request packet that is sent over the RapidIO serial interface.
The testbench cycles from 8 to MAX_WRITTEN_BYTES in steps of 8 bytes. Two tasks are
run to carry out the burst writes, rw_addr_data and rw_data. The rw_addr_data task
initiates the burst and the rw_data task completes the remainder of the burst.
The sister_rio module receives the NWRITE request packets and presents them across
the I/O master Avalon-MM slave interface as write transactions. The testbench calls
the read_writedata task of the sister_bfm_io_write_slave module. The task captures
the written data. The written data is checked against the expected value.
Table 7–4. NWRITE Transactions
Module
Register
Address
Name Value Description
rio 0x1040C
Input/Output Slave
Mapping Window 0
Control
32'h0055_0000 or
32'h5555_0000
Sets the DESTINATION_ID for outgoing
transactions to the value 0x55 or 0x5555,
depending on the device ID width of the
sister_rio. This value matches the base device ID
of the sister_rio. Sets the write request type back
to NWRITE.