16.3 Introduction

This macro library guide supports the RTG4™ FPGA family. See the Microchip website for macro guides for other families. This guide follows a naming convention for sequential macros that is unambiguous and extensible, making it possible to understand the function of the macros by their name alone.

The first two mandatory characters of the macro name indicates the basic macro function:

• DF—D-type flip-flop

The following mandatory character indicates the output polarity:

• I—output inverted (QN with bubble)
• N—output non-inverted (Q without bubble)

The following mandatory number indicates the polarity of the clock or gate:

• 1—rising edge-triggered flip-flop or transparent high latch (non-bubbled)
• 0—falling edge-triggered flip-flop or transparent low latch (bubbled)

The following two optional characters indicate the polarity of the Enable pin, if present:

• E0—active-low enable (bubbled)
• E1—active-high enable (non-bubbled)

The following two optional characters indicate the polarity of the asynchronous Preset pin, if present:

• P0—active-low asynchronous preset (bubbled)
• P1—active-high asynchronous preset (non-bubbled)

The following two optional characters indicate the polarity of the asynchronous Clear pin, if present:

• C0—active-low asynchronous clear (bubbled)
• C1—active-high asynchronous clear (non-bubbled)

All sequential and combinatorial macros (except MX4 and XOR8) use one logic element in the RTG4 family.

For example, the macro DFN1E1C0 indicates a D-type flip-flop (DF) with a non-inverted (N) Q output, positive-edge-triggered (1), with Active-High Clock Enable (E1) and Active-Low Asychronous Clear (C0). See the following figure.