ECP5 and ECP5-5G High-Speed I/O Interface
Technical Note
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FPGA-TN-02035-1.3
The Pause_sync output of the MEM_SYNC soft IP is used to request DQSBUFM pause for the DDRDLL update and
goes to an output port of the Clarity Designer module. The input port Pause_data goes to DQSBUFM. It is required
by user logic, to OR the Pause_sync output of the MEM_SYNC module with the user pause to drive the Pause_data
input of the DQSBUFM. This OR would need to be implemented outside of the Clarity Designer module in your
design.
CLKDIVF set to divide by 2 function is used to generate the SCLK from the ECLK.
When DDR data bus is required to cross two sides, an ECLKBRIDGECS should be enabled in Clarity Designer. When
using ECLKBRIDGECS, there are two DDRDLLs in the design one for each side. Also the DQSBUFMs used on the
second side should be connected to its DDRDLL. Clarity Designer automatically generates all the required DDRDLLs
and DQSBUFMs.
6.3.2.
Write Implementation (DQ, DQS, and DM)
shows the DDR2, DDR3/DDR3L, LPDDR2, and LPDDR3 memory interface write side implementation to
generate DQ, DQS, and DM outputs.
Q
DDR_reset
dqs _0
dq_0(0)
dq_0(7)
dm_0
Q
Q
Q
Q
Q
Eclk (from ECLKSYNCA as shown in the Input interface)
Sclk (from CLKDIVF as shown in the Input interface)
DQSW270 (from DQSBUFM as shown in the Input interface)
DQSW (from DQSBUFM as shown in the Input interface)
dqtri_0(0)
dqtri_0(0)
dataout_0(8)
dataout_0(0)
dataout_0(16)
dataout_0(24)
dataout_0(15)
dataout_0(7)
dataout_0(23)
dataout_0(31)
1'b0
dqso_0(0)
1'b0
dqso_0(1)
dqstri_0(0)
dqstri_0(1)
D0
D1
D2
D1
RST
DQSW270
SCLK
ECLK
RST
D0
D1
D2
D3
SCLK
ECLK
DQSW
ODDRX2DQA
ODDRX2DQSB
T0
T1
SCLK
ECLK
DQSW
RST
TSHX2DQSA
D0
D1
D2
D1
RST
DQSW270
SCLK
ECLK
datamask_0(0)
datamask_0(1)
datamask_0(2)
datamask_0(3)
D0
D1
D2
D1
RST
DQSW270
SCLK
ECLK
ODDRX2DQA
T0
T1
SCLK
ECLK
DQSW270
RST
TSHX2DQA
ODDRX2DQA
Figure 6.9. DDR2, DDR3/DDR3L, LPDDR2, and LPDDR3 Write Side (DQ, DQS, and DM)