Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1
532
UG586 November 30, 2016
Chapter 4:
LPDDR2 SDRAM Memory Interface Solution
The desired input clock period is selected from the list. These values are determined by the
memory clock period chosen and the allowable limits of the parameters. For more
information on the MMCM parameter limits, see
Click
Next
to display the
FPGA Options
page.
FPGA Options
shows the
FPGA Options
page.
•
System Clock
– This option selects the clock type (Single-Ended, Differential, or No
Buffer) for the
sys_clk
signal pair. When the
No Buffer
option is selected, IBUF
primitives are not instantiated in RTL code and pins are not allocated for the system
clock.
If the designs generated from MIG for the
No Buffer
option are implemented without
performing changes, designs can fail in implementation due to IBUFs not instantiated
for the
sys_clk_i
signal. So for No Buffer scenarios,
sys_clk_i
signal needs to be
connected to an internal clock.
X-Ref Target - Figure 4-21
Figure 4-21:
FPGA Options