The <pins> section lists all the pins on the defined <component>, as well as properties associated with those pins. The <pins> section can include one or more <pin> tags nested within.
The same properties can be defined with the <component pin_map_file="”> attribute. However, the property values defined in the <pins> section take precedence over the property values defined in the "pin_map_file=.”
The <pins> section lets you override the general pin properties defined in the “pin_map_file” with specific property values for specific circumstances. For instance, when pins with different properties, like IOSTANDARD, share the same pins of an FPGA (or any other component) through a switch or a jumper, the pin properties can be defined in the <pins> section to override the pin properties defined in the “pin_map_file” for the same pin.
<pins>
<pin index="0" name="rs232_uart_USB_TX" iostandard="LVCMOS25"/>
<pin index="1" name="rs232_uart_USB_RX" iostandard="LVCMOS25"/>
</pins>