Xilinx Zynq-7000 - Page 70

Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1 70
UG586 November 30, 2016
www.xilinx.com
Chapter 1: DDR3 and DDR2 SDRAM Memory Interface Solution
DATA_PATTERN
This parameter sets the data pattern
circuits to be generated through RTL
logic. For larger devices, the
DATA_PATTERN can be set to
“DGEN_ALL,” enabling all supported
data pattern circuits to be
generated. In hardware, the data
pattern is selected and/or changed
using vio_data_value_mode. The
pattern can only be changed when
DATA_PATTERN is set to DGEN_ALL.
Valid settings for this parameter are:
• ADDR (default): The address is used as a
data pattern.
• HAMMER: All 1s are on the DQ pins
during the rising edge of DQS, and all 0s
are on the DQ pins during the falling edge
of DQS.
• WALKING1: Walking 1s are on the DQ pins
and the starting position of 1 depends on
the address value.
• WALKING0: Walking 0s are on the DQ pins
and the starting position of 0 depends on
the address value.
• NEIGHBOR: The Hammer pattern is on all
DQ pins except one. The address
determines the exception pin location.
• PRBS: A 32-stage LFSR generates random
data and is seeded by the starting
address.
• DGEN_ALL: This option turns on all
available options:
0x1: FIXED – 32 bits of fixed_data.
0x2: ADDRESS – 32 bits address as data.
0x3: HAMMER
0x4: SIMPLE8 – Simple eight data pattern
that repeats every eight words.
0x5: WALKING1s – Walking 1s are on the
DQ pins.
0x6: WALKING0s – Walking 0s are on the
DQ pins.
0x7: PRBS – A 32-stage LFSR generates
random data.
0x9: SLOW HAMMER – This is the slow
MHz hammer data pattern.
0xA: PHY_CALIB pattern – 0xFF, 00, AA, 55,
55, AA, 99, 66. This mode only generates
READ commands at address zero.
CMDS_GAP_DELAY
This parameter allows pause delay
between each user burst command.
Valid values: 0 to 32.
SEL_VICTIM_LINE
Select a victim DQ line whose state
is always at logic High.
This parameter only applies to the Hammer
pattern. Valid settings for this parameter are
0 to NUM_DQ_PINS.
When value = NUM_DQ_PINS, all DQ pins
have the same Hammer pattern.
Table 1-11: Traffic Generator Parameters Set in the example_top Module (Cont’d)
Parameter Description Value
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