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22 Sept 2016
v1.1
SMA Data TX/RX_P/N pairs
The PZCC-FMC-V2 has four MGT Data SMA Female connectors for differential TX_P/N and
RX_P/N data connections. These I/O’s are not DC blocked on the carrier. If DC blocking is
required for your application, Avnet recommends using an inline capacitor, such as the Fairview
part:
http://www.fairviewmicrowave.com/inner-dc-block-5-mhz-18-ghz-sma-connectors-sd3241-p.aspx
The data connections are listed in
Table 13 – MGT Pin Assignments
2.11
USB UART – J1
The PZCC-FMC-V2 implements a USB-to-UART bridge connected to a PS UART peripheral. U1 is a
Silicon Labs CP2104 USB-to-UART Bridge device and allows connection to a host computer via USB.
The CP2104 connects to the USB Micro AB connector, J1. Basic TXD/RXD connection is implemented.
When the port is not in suspend mode, LED D1 illuminates.
The USB UART interface is designed to operate in bus powered mode. In this mode the UART is
powered solely from the host PC’s USB connection. This mode does not require the carrier to be turned
on. Once enumeration is complete, the communication port with the PC will remain persistent as long as
the USB cable is plugged in. The carrier may be power cycled or reset without loss of the port connection
which is useful in the event a user wants to monitor the UART outputs on a terminal window.
Silicon Labs provides royalty-free Virtual COM Port (VCP) drivers which permit the CP210x USB-to-UART
bridge to appear as a COM port to host computer communications application software (for example,
HyperTerminal or Tera Term). Please refer to the
Silicon Labs CP210x USB-to-UART Setup Guide
. Note that each CP2104 ships with a unique ID and appears as a unique
device when connected to a PC. Windows will enumerate multiple PicoZed FMC Carrier boards with a
unique COM port for each one. This means that multiple PicoZed FMC Carriers can be connected to a
single PC without issue.
The uart1 Zynq PS peripheral is accessed through MIO Bank 1/501 (1.8V). 3.3V to 1.8V level translators
are placed on the data lines to allow this data connection.
SOM Net Name:
Carrier Net Name:
JX3 Pin:
USB_UART_RXD
USB_UART_RXD
42
USB_UART_TXD
USB_UART_TXD
44
Table 14 – CP2104 Connections
USB circuit protection
USB data lines, D+/-, are ESD protected with Bourns ESD diode array, CDSOT23-SR208
.
Figure 10 – ESD Protection
USB
Conn
CP2104
D+
D-
