|
X-Ref Target - Figure 2-36 
|
Description
A port is a special type of hierarchical pin, providing an external connection point at the top-level of a hierarchical design, or an internal connection point in a hierarchical cell or block module to connect the internal logic to the pins on the hierarchical cell. Ports can be scalar, containing a single connection, or can be bus ports to group multiple signals together.
Related Objects
Ports at the top level of the design make connection outside the FPGA through the PACKAGE_PINs of the device package, to IO_BANKs on the die, with assigned IOSTANDARDs.
Ports can also carry clock definitions onto the design from the system or board, and should be assigned external system-level path delay using the set_input_delay or set_output_delay constraints. Refer to the Vivado Design Suite User Guide: Using Constraints (UG903) [Ref 19] for more information on these constraints.
You can query the ports assigned to specific package_pins, IO_banks, IO_Standards, sites, cells, nets, clocks, timing_paths, or drc_violations using a Tcl command like the following:
get_ports -of [get_clocks]
Inside the design, ports are connected to cells, through nets, to build the hierarchical netlist. You can query the objects associated with a port, such as net, timing_path, site, io_bank, io_standard, package_pin, pkgpin_bytegroup, pkgpin_nibble, using the following form of command:
get_package_pins -of [all_inputs]
Properties
The properties found on ports objects are as follows, with example values:
Property Type Read-only Visible Value
BOARD_PART_PIN string false true
BOARD_PIN string false false
BUFFER_TYPE enum false true
BUS_DIRECTION enum true true
BUS_NAME string true true
BUS_START int true true
BUS_STOP int true true
BUS_WIDTH int true true
CLASS string true true port
CLOCK_BUFFER_TYPE enum false true
DIFFTERMTYPE bool false false 0
DIFF_PAIR_PORT string true true
DIFF_PAIR_TYPE enum true true
DIFF_TERM bool false true 0
DIRECTION enum false true IN
DQS_BIAS enum false true
DRIVE enum false true 12
DRIVE_STRENGTH enum false false 12
ESSENTIAL_CLASSIFICATION_VALUE int false true
HD.ASSIGNED_PPLOCS string* true true
HD.CLK_SRC string false true
HD.LOC_FIXED bool false false 0
HD.PARTPIN_LOCS string* false true
HD.PARTPIN_RANGE string* false true
HD.PARTPIN_TIEOFF bool false true
HOLD_SLACK double true true needs timing update***
IBUF_LOW_PWR bool false true 0
INTERFACE string false true
INTERMTYPE enum false false NONE
IN_TERM enum false true NONE
IOB enum false true
IOBANK int true true 33
IOSTANDARD enum false true LVCMOS18
IOSTD enum false false LVCMOS18
IO_BUFFER_TYPE enum false true
IS_BEL_FIXED bool false false 1
IS_FIXED bool false false 1
IS_GT_TERM bool true true 0
IS_LOC_FIXED bool false true 1
IS_REUSED bool true true
KEEP string false true
KEEPER bool false false 0
LOAD double false true
LOC site false true IOB_X1Y43
LOGIC_VALUE string true true unknown
NAME string false true reset
OFFCHIP_TERM string false true NONE
OUT_TERM enum false true
PACKAGE_PIN package_pin false true W9
PIN_TYPE enum true false
PIO_DIRECTION enum false true
PULLDOWN bool false false 0
PULLTYPE string false true
PULLUP bool false false 0
SETUP_SLACK double true true needs timing update***
SITE site false false IOB_X1Y43
SLEW enum false true
SLEWTYPE enum false false
SLEW_ADV enum false false
UNCONNECTED bool true true 0
USE_INTERNAL_VREF enum false true
VCCAUX_IO enum false true
XLNX_LINE_COL int false false
XLNX_LINE_FILE long false false
X_INTERFACE_INFO string false true
The properties of ports can be listed with the following command:
report_property -all [lindex [get_ports] 0]