User manual

Zybo Z7 Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
Page 24 of 31
can also be done in the codec. Configuration is read out and written by accessing the register map via I2C transfers.
The register map is described in the SSM2603 datasheet.
A demo project that uses the Zybo Z7 audio codec in a bare-metal application can be found on the Zybo Z7
Resource Center. The audio codec is also supported in Petalinux generated embedded Linux systems, and will
appear as a standard ALSA audio device.
13 Basic I/O
The Zybo Z7 board includes four slide switches, four push-buttons, four individual LEDs, and two tri-color LEDs
connected to the Zynq PL, as shown in Figure 13.1 (the Zybo Z7-10 only has one tri-color LED). There are also two
pushbuttons and one LED connected directly to the PS via MIO pins, also shown in Figure 13.1. The push-buttons
and slide switches are connected to the Zynq via series resistors to prevent damage from inadvertent short circuits
(a short circuit could occur if a pin assigned to a push-button or slide switch was inadvertently defined as an
output). The push-buttons are “momentary” switches that normally generate a low output when they are at rest,
and a high output only when they are pressed. Slide switches generate constant high or low inputs depending on
their position.
Figure 13.1. Zybo Z7 GPIO.
The high-efficiency LEDs are anode-connected to the Zynq via 330-ohm resistors, so they will turn on when a logic
high voltage is applied to their respective I/O pin. Additional LEDs that are not user-accessible indicate power-on,
FPGA programming status, and USB and Ethernet port status.
The LED and two pushbuttons attached directly to the PS are accessed using the Zynq GPIO controller. This core is
described in full in Chapter 14 of the Zynq Technical Reference Manual.
13.1 Tri-Color LEDs
The Zybo Z7-20 board contains two tri-color LEDs and the Zybo Z7-10 contains one tri-color LED. Each tri-
color LED has three input signals that drive the cathodes of three smaller internal LEDs: one red, one blue, and one