8542 39 19: Elektronik entegre devreler, diğerleri

This heading includes interchangeable pre-programmed memory modules in the form of a monolithic integrated circuit for electronic translation devices falling in subheadings 8470 10 00 and 8543 70 10.

This heading does not include discs (sometimes referred to as wafers) which, for the purposes of their applications in the field of electronics, consist of doped chemical elements, whether or not polished and whether or not epitaxially coated, provided that they have not been selectively doped or diffused to create discrete regions (heading 3818 00).

These subheadings include:

1. full custom logic circuits which are defined by and produced for a single user. The manufacturing process involves routing and placement of cells (logic gates), using fully customised diffusion masks. Full custom logic circuits are designed to perform application-specific functions. They are known as application-specific integrated circuits, so called ASICs;

2. gate arrays which are integrated logic circuits, consisting of a fixed and regular arrangement of uncommitted logic elements (transistor cells of, for example, AND-, NAND-, OR- or NOR- gates). Gate arrays are programmed in accordance with user-specific interconnection of these logic elements by one or more metallisation patterns;

3. standard cells which are integrated logic circuits, consisting of a user-specific arrangement of predefined subcircuits and fixed subcircuits. These subcircuits may contain any integrated function (for example, a logic function or a memory function);

4. programmable logic circuits which are integrated circuits, consisting of fixed logic elements. The eventual function of these circuits is determined by the user by blowing fusible links or by electrically programming the interconnections between the logic elements;

5. standard logic circuits which are integrated logic circuits consisting of less than 150 logic gates (for example, AND, NAND, OR, NOR). These devices may integrate several functions or sets of identical and independent functions;

6. interface circuits which are integrated circuits which perform a link function (for example, by code conversion, by conversion between bit-serial and bit-parallel or by synchronization) to interconnect programs, integrated circuits, peripherals or systems with different characteristics;

7. microperipherals which are integrated circuits performing specific functions to complement microprocessors, microcontrollers or microcomputers and improve their external communication, control and interface features.

Technical specifications of a microperipheral clearly express its relationship with and dedication to a microprocessor, microcontroller or microcomputer.

Communications, control and interface features may consist of bus controllers, memory controllers (DRAM controllers, memory management units (MMUs), direct memory access controllers) or peripheral interface controllers (graphic controllers, local area network controllers, universal asynchronous receiver/transmitter controllers, keyboard controllers, mass storage controllers);

8. smartpower circuits which are integrated analogue circuits which combine digital and analogue circuitry (power transistors) to control logic output signals and power output signals. These devices are able to provide, for example, internal power dissipation protection, fault management or diagnostic capabilities.

These subheadings do not include programmable read only memories (PROMs) (subheading 8542 32 90).

See the HS Explanatory Note to heading 8542, (III).