Data Sheet
3/8/2018 Arty Z7 Reference Manual [Reference.Digilentinc]
https://reference.digilentinc.com/reference/programmable-logic/arty-z7/reference-manual 12/24
SD_CCLK Clock MIO40 5
SD_CMD Command MIO41 3
SD_CD Card Detect MIO47 9
Table 7.1. microSD pinout
The SD slot is a powered from 3.3V, but is connected through MIO Bank 1/501 (1.8V). Therefore, a TI TXS02612 level shifter performs
this translation. The TXS02612 is actually 2-port SDIO port expander, but only its level shifter function is used. The connection diagram
can be seen on Figure 7.1. Mapping out the correct pins and configuring the interface is handled by the Arty Z7 Zynq presets file, available
on the Arty Z7 Resource Center (https://reference.digilentinc.com/reference/programmable-logic/arty-z7/start).
(https://reference.digilentinc.com/_detail/reference/programmable-logic/arty-z7/arty-z7-microsd.png?id=reference%3Aprogrammable-logic%3Aarty-
z7%3Areference-manual)
Figure 7.1. microSD slot signals
Both low speed and high speed cards are supported, the maximum clock frequency being 50 MHz (). A Class 4 card or better is
recommended.
Refer to section 3.1 for information on how to boot from an SD card. For more information, consult the Zynq Technical Reference
manual (http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf).
The Arty Z7 implements one of the two available PS USB OTG interfaces on the Zynq device. A Microchip USB3320 USB 2.0 Transceiver
Chip with an 8-bit ULPI interface is used as the PHY. The PHY features a complete HS-USB Physical Front-End supporting speeds of up
to 480Mbs. The PHY is connected to MIO Bank 1/501, which is powered at 1.8V. The usb0 peripheral is used on the PS, connected
through MIO[28-39]. The USB OTG interface is configured to act as an embedded host. USB OTG and USB device modes are not
supported.
The Arty Z7 is technically an “embedded host”, because it does not provide the required 150 µF of capacitance on VBUS required to qualify
as a general purpose host. It is possible to modify the Arty Z7 so that it complies with the general purpose USB host requirements by
loading C41 with a 150 µF capacitor. Only those experienced at soldering small components on PCBs should attempt this rework. Many
USB peripheral devices will work just fine without loading C41. Whether the Arty Z7 is configured as an embedded host or a general
purpose host, it can provide 500 mA on the 5V VBUS line. Note that loading C41 may cause the Arty Z7 to reset when booting embedded
Linux while powered from the USB port, regardless of if any USB device is connected to the host port. This is caused by the in-rush current
that C41 causes when the USB host controller is enabled and the VBUS power switch (IC9) is turned on.
Note that if your design uses the USB Host port (embedded or general purpose), then the Arty Z7 should be powered via a battery or wall
adapter capable of providing more power (such as the one included in the Arty Z7 accessory kit).
8 USB Host
9 Ethernet PHY
