6
ECP5 and ECP5-5G Hi
g
h-Speed I/O Interface
Hi
g
h-Speed DDR Interface Details
This section describes each of the generic high-speed interfaces in detail, including the clocking to be used for
each interface. For detailed information about the ECP5 and ECP5-5G device clocking structure, refer to TN1263,
ECP5 and ECP5-5G sysClock PLL/DLL Design and Usage Guide
. The various interface rules listed under each
interface should be followed to build these interfaces successfully. Refer to the
Timing Analysis for High Speed
section of this document for more information about the timing analysis on these interfaces.
Some of these interfaces may require a soft IP in order utilize all the features available in the hardware. These soft
IP cores are available in Clarity Designer and are described in this section. Some of the soft IPs are optional and
can be selected in the Clarity Designer. Some of these are mandatory for the module to function as expected and
will automatically be generated when building the interface through Clarity Designer.
GDDRX1_RX.SCLK.Centered
This a Generic 1X gearing Receive interface using SCLK. The clock is coming in centered to the Data. This inter-
face must be used for speeds below 200
MHz
.
This DDR interface uses the following modules:
• IDDRX1F element to capture the data
• The incoming clock is routed through the Primary (SCLK) clock tree
• Static data delay element DELAYG is used to delay the incoming data enough to remove the clock injection time.
• Optionally the user can choose to use Dynamic Data delay adjustment using DELAYF element to control the
delay on the DATA dynamically. DELAYF will also allow user to override the input delay set. The type of delay
required can be selected through Clarity Designer.
• DEL_MODE attribute is used with DELAYG and DELAYF element to indicate the interface type so that the cor-
rect delay value can be set in the delay element.
The following figures show the static delay and dynamic delay options for this interface.
Figure 4. GDDRX1_RX.SCLK.Centered Interface (Static Delay)
Figure 5. GDDRX1_RX.SCLK.Centered Interface (Dynamic Data delay)
IDDRX1F
SCLK
D
Q0
Q1
RST
AO
DELAYG
Z
Datain
Q[0]
Q[1]
Clkin
Reset
DEL_MODE =
SCLK_CENTERED
Sclk
IDDRX1F
SCLK
D
Q0
Q1
RST
Datain
Reset
Q [ 0 ]
Q [ 1 ]
Z
A
DELAYF
LOADN
MOVE
DIRECTION
Z
data_cflag
data_loadn
data_move
data_direction
Clkin
(Optional)
DEL_MODE=SCLK_CENTERED
Sclk