61
ECP5 and ECP5-5G Hi
g
h-Speed I/O Interface
DELAY Attribute Description
Table 17 describes the attributes available for the DELAYF and DELAYG elements. The value of DEL_MODE is
selected based on the interface that will be generated. These values are used to compensate for the clock injection
time, hence should be selected based on clocking used. IP Express will automatically assign the correct values for
this attribute when Clarity Designer is used to build the interface.
Table 17. DELAYF and DELAYG Attributes
DDRDLL (Master DLL)
The DDRDLL is used to generate a 90 degree delay for the DQS Strobe Input during a memory interface or for the
clock input for a generic DDR interface.
There is one DDRDLL module on each corner of the device. The DDRDLL outputs delay codes that are used in the
DQSBUF elements to delay the DQS input, or in the DLLDEL module to delay the input clock. DDRDLL by default
will generate 90degree phase shift.
DDRDLLA
Figure 53. DDRDLLA Primitive
Attribute
Description
Values
1, 2, 3, 4
Default
DELAY
DEL_MODE
Sets the delay mode to be used
USER_DEFINED
SCLK_ZEROHOLD
ECLK_ALIGNED
ECLK_CENTERED
SCLK_ALIGNED
SCLK_CENTERED
ECLKBRIDGE_ALIGNED
ECLKBRIDGE_CENTER
ED
DQS_CMD_CLK
DQS_ALIGNED_X2
USER_DEFINE
D
DELAYG
DELAYF
DEL_VALUE
Sets delay value when
DEL_MODE is set to
USER_DEFINED
0..127
0
DELAYG
DELAYF
1. DEL_MODE must be ECLKBRIDGE_ALIGNED or ECLKBRIDGE_CENTERED when it is required to place the data pins of the same hi-
speed interface on the other side of the device. In addition to setting the DEL_MODE attribute it is also require to instantiate the ECLK-
BRIDGECS element in the HDL design.
2. DQS_CMD_CLK is only for the DDR Memory CMD and CLK Outputs.
3. DQS_ALIGNED_X2 is shared by DQS Generic and the DDR Memory Inputs.
CLK
RST
UDDCNTLN
FREEZE
DDRDEL
LOCK
DDRDLLA
DCNTL[7:0]