Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1
395
UG586 November 30, 2016
Chapter 3:
RLDRAM II and RLDRAM 3 Memory Interface Solutions
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.
•
Reference Clock
– This option selects the clock type (Single-Ended, Differential, No
Buffer, or Use System Clock) for the
clk_ref
signal pair. The
Use System Clock
option
appears when the input frequency is between 199 and 201 MHz (that is, the Input Clock
Period is between 5,025 ps (199 MHz) and 4,975 ps (201 MHz). When the
No Buffer
option is selected, IBUF primitives are not instantiated in RTL code and pins are not
allocated for the reference clock.
X-Ref Target - Figure 3-20
Figure 3-20:
FPGA Options Page