WB_PRTIO - Configurable Wishbone Parallel Port Unit (AD10)
Contents
Altium Designer 10 delivers an enhanced configurable Wishbone Parallel Port Unit (WB_PRTIO), configuration of which is far more powerful and intuitive. No longer are you constrained to having a peripheral configurable to 1, 2 or 4 ports only. Now you can add and define as many ports as you'd like – ensuring that your design needs are not inhibited in any way. What's more, you are not confined to having all ports a single, defined width and kind. Each port is definable in its own right. In other words, each port is configured individually to suit your design requirements.
Specifying Port Signals
Each individual port (or register) interface within the unit is defined in terms of the following information:
- Name – a meaningful name for the incoming and/or outgoing signal. A signal can be from 1 to 32 bits in width. Specify the required width as part of the signal name. For example, a single bit signal would require just a name (e.g.
FLAG
). A 32-bit signal would require a name and a bus index suffix (e.g.FLAG[31..0]
).
- Kind – what type of signal it is. A signal can be either an input (Kind =
In
), an output (Kind =Out
), or both input and output (Kind =In/Out
). There is no Tristate kind. Where such a type has been defined for the component in a previous release of Altium Designer, the port interface will be translated to two entries in its corresponding configuration – one signal of kindIn/Out
and an additional signal for the tristate pin, with kind set toOut
, as illustrated in the following image.
When configuring the parallel port unit placed on a schematic sheet, a third piece of information is used when defining the signal – Space After. This field is used to determine the amount of blank space that is inserted after the pin(s) for that port interface.
Adding and Removing Signals
When you initially place a parallel port unit a single port interface is defined, with signal name PA[7..0]
and kind set to In/Out
. Change the signal's Name and/or Kind as required. To add a new signal (port/register interface) to the unit, simply click the Add button. A new signal entry will be added to the Signals list. By default, new signals are added with naming in the format PA[7..0]
, PB[7..0]
, and so on. Signal width is 8 bits and kind is set to In
. Again, change the definition of each signal added as required for your design.
Removal of signals is simply a case of selecting them in the list – use Ctrl+click and Shift+click to select multiple signals – and then clicking the Remove button.
Changing Interface Ordering
After defining the port signals, you may find that you want to change the order in which their corresponding interfaces appear – on the WB_PRTIO's schematic symbol, or in the external interface signals fed from the OpenBus System to the parent sheet symbol above. Support for interface reordering is provided through two additional buttons in the dialog
– Move Up and Move Down.
Pasting Signals using Windows Clipboard Content
To aide in setting up signals in a more expedient manner, the configuration dialog supports the ability to paste content from the Windows clipboard, through the additional Paste button. You can use this time-saving feature to paste, for example, a column of copied signal names from an external application such as a spreadsheet or a text editor. Closer to home, you can select net labels in a schematic, use the standard Ctrl+C shortcut to copy their content to the clipboard, then paste them into the configuration dialog.
Signals added using the paste feature will have Kind set to In/Out
and, for a WB_PRTIO component placed on a schematic, Space After set to 0
. Make changes as required for your design.