is an I/O Pad or standard-cell(CORE)
MTC_IOPAD = 0, MTC_CORE, MTC_BLOCK, MTC_OTHER, MTC_LUT, MTC_FF, MTC_DSP, MTC_RAM, MTC_IO, MTC_CARRY8, MTC_HalfCLB
Some Knowledge
原文：https://www.cnblogs.com/How-Come/p/11038588.html
