Because Lever macros are segments of software code rather than physical components, the term "macro" is used when referring to gates, flip-flops, counters, etc. Macros are kept in library files. Luckily, the Macro Library Reference Manual provides the same type of information as do data sheets for physical components. Here are tips for using the reference manual:

1. Open the schematic editor.
2. Click Help, Schematic Editor Help in the menu bar.
3. Under Concepts, choose Schematic Library Support (at the very bottom).
4. Choose ispLSI Macro Library Reference Manual.
5. Counters obviously are under Counters, and gates are obviously under Logic Gates.
6. Not so obviously, flip-flips are under Registers.
• What are normally called RS flip-flops are listed as SR Latches (where SR means "set, reset" rather than "shift register").
• D flip-flops have a clock input, whereas D latches do not.
7. Shift registers are also under Registers.
8. If you know the number of the macro, but don't know what it stands for, there is an aphabetical list under Index.

Macro names follow a certain pattern. Many macros have different levels of sophistication. Type 1 devices are the simplest, type 2 devices have more features, etc.

Here are some macro name examples:

Counters

• CBD14 means "Counter, binary down, type 1, 4 bits." In other words, a type one  4-bit down-counter.
• CBU14 means "Counter, binary up, type 1, 4 bits." In other words, a type one  4-bit up-counter.
• CBU44 is a type four 4-bit up-counter, and has more features than does a type one up-counter.
• CBUD4 is a 4-bit up/down counter. Evidently, for up/down counters, you don't get choices as to the degree of sophistication.

Shift Registers

• SRR14 means "Shift register, right-shift, type 1, 4-bits."
• SRRL4 means "Shift register, right/left-shift, 4-bits." As with up/down counters, there is only one level of sophistication for right/left shift registers.