home *** CD-ROM | disk | FTP | other *** search
- ≡
- GROUP
- Overview
- The keyword of a statement that clusters several pins or nodes under a
- single name. Then you can use the group name in the equations or
- state segment of your design.
-
-
- Syntax───────────────────────────────────────────────────────────────
- GROUP Group_Name Pn_List
-
- ─────────────────────────────────────────────────────────────────────
-
- Device Support: All PLD devices.
- ·
- Syntax
- You use the keyword, GROUP, in the declaration segment of Boolean and
- state-machine designs.
-
- Syntax───────────────────────────────────────────────────────────────
- GROUP Group_Name Pn_List
- Example──────────────────────────────────────────────────────────────
- PIN 15 OUT1 COMB
- PIN 16 OUT2 COMB
- NODE 5 NB COMB
- GROUP BANK1 OUT1 OUT2 NB
- :
- EQUATIONS
- :
- BANK1 = IN1 * IN2 * IN3
- ────────────────────────────────────────────────────────────────────
- ·
- Definitions
-
- Group_Name This is the name assigned to a cluster of pins or
- nodes. The name can then be used in the equations or
- state segments of a design to refer to the entire
- cluster without having to list them separately.
- Follow the rules below.
-
- ■ Assign a unique name of up to 14 alphanumeric
- characters.Do not use keywords, operators, or
- reserved words.
-
- ■ Place the name after the keyword GROUP and before
- the pin or node statements.
-
- The syntax example shows BANK1 as a group name.
-
- Pn_List This is a list of the pins or nodes, defined in the
- pin and node statement, that are associated with the
- group name.
-
- ■ Place this list after the group name.
-
- ■ Separate pin and node names by a single space;
- multiple spaces are reduced to one. Do not use
- commas or any other punctuation. You can use the
- range operator, [], to define a group of pins.
-
- In the syntax example, the equation BANK1 = IN1 * IN2
- * IN3 is automatically expanded into the three
- equations shown below.
-
- OUT1 = IN1 * IN2 * IN3
- OUT2 = IN1 * IN2 * IN3
- NB = IN1 * IN2 * IN3
- ·
- Use
- You can place the GROUP statement either before or after SIGNATURE and
- STRING statements. You can use the group name, wherever appropriate
- in the design file, in place of the defined group of pins or nodes.
- This can simplify the equations segment of the file by reducing the
- number of equations required.
-
- ■ You can only use the group name on the left side of an equation.
-
- ■ You can also use the group name to define pins or nodes in the
- simulation segment.
-
- Note: You can use a group name when controlling registers consisting
- of banks of flip-flops with common reset or other control lines.
-
- For example, use a group name to combine four outputs that share a
- common reset line. The software then writes four .RSTF equations.
-
- ;DECLARATION SEGMENT
- PIN 2 A REG
- PIN 3 B REG
- PIN 4 C REG
- PIN 5 D REG
- PIN 6 E REG
- GROUP QRST A B C D
-
- ;EQUATIONS
- QRST.RSTF = RES
-
- ;This expands to
- A.RSTF = RES
- B.RSTF = RES
- C.RSTF = RES
- D.RSTF = RES
- ·
- Related Topics
- Declaration Segment
- MACH_SEG_A, MACH_SEG_B, MACH_SEG_C, MACH_SEG_D
- NODE
- PIN
- ·
-