The synthesizable traffic generator mode is defined by the value set in the DEFAULT_MODE parameter for each traffic generator instance at the top level of the Example Design. By default this is set to “HBM” but there are additional modes which can be set by the user. The traffic generator will only access the pseudo channel address range associated with the AXI port.
- HBM
- This is a high bandwidth Write and read access pattern. Linear aligned addressing sequence where the writes are performed first and then reads back the entire range while checking for data errors with a PRBS pattern. In hardware this mode will cover the entire pseudo channel address range depending on the stack height of the HBM in the device and will loop indefinitely. In simulation this will perform 256 32-byte bursts for the Write sequence, 256 32-byte bursts for the read sequence, and then stop.
- HBM_WRITE
- This is a high bandwidth Write only access pattern. A PRBS data pattern is used for the Write only linear aligned addressing sequence. In hardware this mode will cover the entire pseudo channel address range depending on the stack height of the HBM in the device and will loop indefinitely. In simulation this will only Write 256 32-byte bursts.
- HBM_READ
- This is a high bandwidth read only access pattern. This is executed as a read only linear aligned addressing sequence. In hardware this mode will cover the entire pseudo channel address range depending on the stack height of the HBM in the device and will loop indefinitely. In simulation this will only read 256 32-byte bursts.
- HBM_W_R
- This is a low bandwidth access pattern since only one Write is executed and then the same address is read back. Linear aligned addressing sequence where a single Write is followed by a single read. The Write and read will alternate while linearly progressing through the address space with error checking on a PRBS data pattern. In hardware this mode will cover the entire pseudo channel address range depending on the stack height of the HBM in the device and will loop indefinitely. In simulation this will perform a total of 256 32-byte bursts for the Write sequence, a total of 256 32-byte bursts for the read sequence, and then stop.
- HBM_RANDOM
- This is an even lower bandwidth access pattern since only one Write is executed and then the same address is read back but the traffic generator moves randomly through the address space which means a high probability of a page miss from the previous random address. This mode uses an aligned PRBS addressing sequence where one Write is followed by one read with a PRBS data pattern and error checking. In hardware this mode will cover the entire pseudo channel address range depending on the stack height of the HBM in the device and will loop indefinitely. In simulation this will perform a total of 256 32-byte bursts for the Write sequence, a total of 256 32-byte bursts for the read sequence, and then stop.