Zybo Z7 Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
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The PL is also cleared during a system reset. System reset does not cause the boot mode strapping pins to be re-
sampled.
7
USB-UART Bridge (Serial Port)
The Zybo Z7 includes an FTDI FT2232HQ USB-UART bridge (attached to connector J12) that lets you use PC
applications to communicate with the board using standard COM port commands (or the tty interface in Linux).
Drivers are automatically installed in Windows and newer versions of Linux when the Zybo Z7 is attached. Serial
port data is exchanged with the Zynq using a two-wire serial port (TXD/RXD). After the drivers are installed, I/O
commands can be used from the PC directed to the COM port to produce serial data traffic on the Zynq pins. The
port is tied to PS (MIO) pins and can be used in combination with the UART 1 controller.
The Zynq presets file (available in the
Zybo Z7 Resource Center
) takes care of mapping the correct MIO pins to the
UART 1 controller and uses the following default protocol parameters: 115200 baud rate, 1 stop bit, no parity, 8-bit
character length.
Two on-board status LEDs provide visual feedback on traffic flowing through the port: the transmit LED (LD11) and
the receive LED (LD10). Signal names that imply direction are from the point-of-view of the DTE (Data Terminal
Equipment), in this case the PC.
The FT2232HQ is also used as the controller for the Digilent USB-JTAG circuitry, but the USB-UART and USB-JTAG
functions behave entirely independent of one another. Programmers interested in using the UART functionality of
the FT2232 within their design do not need to worry about the JTAG circuitry interfering with the UART data
transfers, and vice-versa. The combination of these two features into a single device allows the Zybo Z7 to be
programmed, communicated with via UART, and powered from a computer attached with a single Micro USB
cable.
The connections between the FT2232HQ and the Zynq-7000 are shown in Figure 7.1.
Figure 7.1. UART Connections.
8
microSD Slot
The Zybo Z7 provides a microSD slot (J4) for non-volatile external memory storage as well as booting the Zynq. The
slot is wired to Bank 1/501 MIO[40-45], and also includes a card detect signal attached to MIO 47. On the PS side
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