Zynq-7000 AP SoC and 7 Series FPGAs MIS v4.1
324
UG586 November 30, 2016
Chapter 2:
QDR II+ Memory Interface Solution
lists the signals used in the infrastructure module that provides the necessary
clocks and reset signals required in the design.
Physical Interface
The physical interface is the connection from the FPGA memory interface solution to an
external QDR II+ SRAM device. The I/O signals for this interface are shown in
.
These signals can be directly connected to the corresponding signals on the QDR II+ SRAM
device.
Table 2-8:
Infrastructure Clocking and Reset Signals
Signal
Direction
Description
mmcm_clk
Input
System clock input.
sys_rst
Input
Core reset from user application.
iodelay_ctrl_rdy Input
IDELAYCTRL lock status.
clk
Output
Half frequency FPGA logic clock.
mem_refclk
Output
PLL output clock at same frequency as the memory clock.
freq_refclk
Output
PLL output clock to provide the FREQREFCLK input to the Phaser. The freq_refclk is
generated such that its frequency in the range of 400 MHz to 1,066 MHz.
sync_pulse
Output
PLL output generated at 1/16 of mem_Refclk and is a synchronization signal sent
to the PHY hard blocks that are used in a multi-bank implementation.
pll_locked
Output
Locked output from PLLE2_ADV.
rstdiv0
Output
Reset output synchronized to internal FPGA logic half frequency clock.
Table 2-9:
Physical Interface Signals
Signal
Direction
Description
qdr_cq_n
Input
QDR CQ#
. This is the echo clock returned from the memory derived from
qdr_k_n.
qdr_cq_p
Input
QDR CQ
. This is the echo clock returned from the memory derived from
qdr_k_p.
qdr_d
Output
QDR Data
. This is the write data from the PHY to the
QDR II+ memory
device.
qdr_dll_off_n
Output
QDR DLL Off
. This signal turns off the DLL in the memory device.
qdr_bw_n
Output
QDR Byte Write
. This is the byte write signal from the PHY to the QDR II+
SRAM device.
qdr_k_n
InOut
QDR Clock K#
. This is the inverted input clock to the memory device.
qdr_k_p
InOut
QDR Clock K
. This is the input clock to the memory device.
qdr_q
Input
QDR Data Q
. This is the data returned from reads to memory.
qdr_sa
Output
QDR Address
. This is the address supplied for memory operations.
qdr_w_n
Output
QDR Write
. This is the write command to memory.
qdr_r_n
Output
QDR Read
. This is the read command to memory.