| 摘要 |
An integrated circuit (IC) comprises interface (I/O) circuitry between functional IC circuitry and external components, in which plural interface cells have power supply lines extending across a width and co-operating with power supply line sections of other interface cells, providing a shared power supply rail structure to supply the interface components. Each power supply line section includes a portion DVDD sized to support a current carrying constraint of the interface circuitry and a second portion DVSS sized insufficiently to support that constraint. For each interface cell 100 the second supply line portion is connected to a current carrying structure 115 external to that interface cell, such that the combination supports the current carrying constraint. The cells may be abutting in pairs with DVSS rails abutting and the current carrying structure external to the interface cell provided by the DVSS rails of the paired cell (Fig. 5). Alternatively the functional circuitry may be surrounded by a ring of interface cells, with the external current carrying structure provided in a peripheral part of a distribution (RDL) layer (Fig. 6). A reduction in the area required for the power supply line structure is supported, enabling a reduction in the size of the interface circuitry and of the integrated circuit. |
