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ZC702 Board User Guide
www.xilinx.com
27
UG850 (v1.2) April 4, 2013
Feature Descriptions
FMC Connector JTAG Bypass
When an FPGA mezzanine card (FMC) is attached to J3 or J4 it is automatically added to the
JTAG chain through electronically controlled single-pole single-throw (SPST) switches U25
and U26. The SPST switches are normally closed and transition to an open state when an
FMC is attached. Switch U25 adds an attached FMC to the JTAG chain as determined by the
FMC1_HPC_PRSNT_M2C_B signal. Switch U26 adds an attached FMC to the JTAG chain as
determined by the FMC2_LPC_PRSNT_M2C_B signal.
Clock Generation
The ZC702 board provides three clock sources for the XC7Z020 AP SoC.
Table 1-11
lists the
source devices for each clock.
Table 1-12
lists the pin-to-pin connections from each clock source to the XC7Z020 AP SoC.
Table 1-10:
Switch SW10 JTAG Configuration Option Settings
Configuration Source
DIP Switch SW10[1:2]
Switch 1
(1)
JTAG_SEL_1
Switch 2
(1)
JTAG_SEL_2
None
0
0
Digilent USB-to-JTAG interface U23
1
0
Cable connector J2
(2)
0
1
JTAG header J58
1
1
Notes:
1. 0 = open, 1 = closed
2. Default switch setting
Table 1-11:
ZC702 Board Clock Sources
Clock Name
Clock
Source
Description
System Clock
U43
SiT9102 2.5V LVDS 200 MHz fixed-frequency oscillator (SiTime). See
System Clock
.
User Clock
U28
Si570 3.3V LVDS I
2
C programmable oscillator, 156.250 MHz default (Silicon
Labs). See
Programmable User Clock
.
PS Clock
U65
SIT8103 1.8V single-ended CMOS 33.3333 MHz fixed frequency oscillator
(SiTime). See
Processing System Clock Source
.
Table 1-12:
Clock Connections, Source to XC7Z020 AP SoC
Clock Source Pin
Net Name
XC7Z020 (U1) Pin
U43.5
SYSCLK_N
C19
U43.4
SYSCLK_P
D18
U28.5
USRCLK_N
Y8