Altera Designing With Low-Level Primitives Manual do Utilizador descarregar pdf (Página 23)

Altera Corporation 2–1

April 2007

2. Primitive Reference

Primitives

Using primitives with HDL is an efficient way to make assignments to

your design without using the Assignment Editor.

The Quartus

II software supports the following primitives, described on

the corresponding pages:

■ “ALT_INBUF”

■ “ALT_OUTBUF” on page 2–3

■ “ALT_OUTBUF_TRI” on page 2–6

■ “ALT_IOBUF” on page 2–8

■ “ALT_INBUF_DIFF” on page 2–11 (1)

■ “ALT_OUTBUF_DIFF” on page 2–13 (1)

■ “ALT_OUTBUF_TRI_DIFF” on page 2–14 (1)

■ “ALT_IOBUF_DIFF” on page 2–19 (1)

■ “ALT_BIDIR_DIFF” on page 2–22 (1)

■ “ALT_BIDIR_BUF” on page 2–25 (1)

■ “LCELL” on page 2–27

■ “DFF” on page 2–28

■ “CARRY and CARRY_SUM” on page 2–29

■ “CASCADE” on page 2–30

■ “LUT_INPUT” on page 2–31

■ “LUT_OUTPUT” on page 2–32

Note to the above list:

(1) These I/O primitives are supported only in Stratix

III and Cyclone

III device

families.

ALT_INBUF

The primitive allows you to make a location assignment, termination

assignment, and also lets you determine whether to use weak pull up

resistor, whether to enable bus-hold circuitry or an io_standard

assignment to an input pin from a lower-level entity. Table 2–1 describes

1 2 ... 18 19 20 21 22 23 24 25 26 27 28 ... 55 56

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