
12
ECP5 and ECP5-5G Hi
g
h-Speed I/O Interface
• The ECLKBRIDGE can be optionally enabled if the data bus will be crossing over between the left and right sides
of the device. If ECLKBRIDGE is enabled then the ECLKBRIDGECS element should be used in the interface
before the ECLKSYNCB element. This element can be enabled through Clarity Designer.
Figure 12. GDDRX2_RX.MIPI
Interface Requirements
• The clock input must use a PCLK input so that it can be routed directly to the edge clock tree.
• ECLK must use the Edge clock tree and the SCLK out of the CLKDIVF must use the Primary clock tree, software
will error out if these dedicated clock routes are not used
• “USE PRIMARY” preference may be assigned to the SCLK net
• The user must set the timing preferences as per section “Timing Analysis Requirement”
GDDRX71_RX.ECLK
This interface is used to implement 7:1 LVDS Receiver interface using the 1 to 7 gearing with ECLK. Slow speed
clock coming in is multiplied 3.5X using a PLL. This clock is used to capture the data at the receiver IDDRX71 mod-
ule.
This DDR interface uses the following modules:
• IDDRX71B element is used to capture the data
• EHXPLLK will multiply the input clock by 3.5 and phase shift the incoming clock based on the dynamic phase
shift input.
• This clock is routed to the Edge clock (ECLK) clock tree through the ECLKSYNCB module
• CLKDIVF module is used to divide the ECLK by 3.5 and is routed to the primary clock tree used as the SCLK
input
• A second IDDRX71B element is used with data connected to clock input to generate 7 bit clock phase that can
be used for word alignment
• The startup synchronization soft IP (GDDRX_SYNC) is required for this interface to tolerate the skew between
the ECLKSYNCB Stop input and the Reset to the DDR and CLKDIV modules.
• An optional Bit and Word alignment soft IP(BW_ALIGN) can be enabled in Clarity Designer. The Bit alignment
module will rotate PLL’s 16 phases to center Edge clock to middle of data eye and the word alignment module will
use ALIGNWD function of CLKDIVD and IDDRX71B to achieve 7-bit word alignment
• The ECLKBRIDGE can be optionally enabled if the data bus will be crossing over between the left and right sides
of the device. If ECLKBRIDGE is enabled then the ECLKBRIDGECS element should be used in the interface
before the ECLKSYNCB element. This element can be enabled through Clarity Designer.
Data_P
Data_N
hsdatasel
ALIGNWD
A
DELAYG
Z
ECLKI
STOP
ECLKO
SCLK
D
Q[3:0]
ST
ALIGNWD
ECLK
IDDRX2F
Primary
Sclk
CLKDIVF
CLKI
RST
CDIVX
Alignwd
Q[3:0]
ECLKSYNCB
DEL_MODE=
ECLK_CENTERED
A
AN
HSSEL
OLSO0
A
AN
HSSEL
OHSOLS1
Clk_P
Clk_N
hsclksel
ALIGNWD
sync_reset
GDDR_SYNC
Sync_clk
Start
RST
START
SYNC_CLK
DDR_RESET
STOP
READY
Ready
OLS0
OHSOLS1
Edge
lsdatain[1]
lsdatain[0]
lsclkin[0]
lsclkin[1]