Dear FPGA colleagues,

please, for short ignore the fact that XPS is discontinued 
implementation tool by Xilinx - I have to use it now.

Problem:
I remember having instatiated IOBUFS inside the top-level MHS-file of a 
FPGA project. But I can't remeber how this was done. One way is to do 
the following:

PORT i2c_sda_0_I = "", DIR = I
PORT i2c_sda_0_O = "", DIR = O
PORT i2c_sda_0_T = "", DIR = O
PORT i2c_sda_0 = "", DIR = IO, THREE_STATE = TRUE, TRI_I = i2c_sda_0_I, 
TRI_O = i2c_sda_0_O, TRI_T = i2c_sda_0_T

where now i2c_sda_0 is the IO inout of the IOBUFFER.

Assume I have a signal "to_z_iobuf" that is constantly high and I want 
it to put it onto the tri-state enable input T of the IOBUF such that 
the FPGA pad is constantly on high impedance 'Z'.

Can I do:
BEGIN IOBUF
 PARAMETER INSTANCE = iobuf_inst01
 PORT I = proc_sys_reset_0_BUS_STRUCT_RESET
 PORT LMB_CLK = clk_120_0000MHz
END

Or am I completely wrong and there is no way to separately instantiate 
them inside the MHS?

Cheers
Markus