The correct way is often the way that works for you.
Devices like PLCCs are not really the same as something like a LS7400
where all the pins have a specific fixed functions.
With PLCC's and uP's it makes for much better reading if the pins are
named for the function that they are providing for the project.
i.e. If I use a PIC microcontroller for a project, I would grab the
basic component, make a copy and name the pins for what I need, such as
display1, 2, 3, temp-sensor1, speed-sensor etc. This makes it much easier
to read the circuit rather than seeing a pin that can be configured for
multiple functions and wondering what I decided to use it for.
(Especially when coming back to the design after a while)
In the case of the 230, it would seem to make most sense to
group the i/o pins into the 8 pin blocks as per the datasheet and leave
it at that.
The Vcc's can be grouped, as can the other few functions. You don't really
want to mix other functions within the general purpose i/o, that just
makes drawing up the circuit rather messy.
Andy
On Thu, 13 Sep 2018 12:27:47 +0100
"Derek derek@... [kicad-users]" <kicad-users@...> wrote:
Hi,
I am learning how to create schematic symbols using the Component Library Editor.
The proces for creation of schematic symbols is easy to use. But I need some advice on the format of the creation of a symbol for a Lattice MACH 230.
The MACH 230 is a 84 pin PLCC, which the pin connections are:
64 I/O pins
6 Vcc pins
8 GND
4 CLOCK / Input
2 Input
I started out creating the smybol as detailed in the Datasheet, but have read the KiCad Library Convention.
Section S4.2 indicates that pins should be grouped by function.
If I follow the convention, all 64 I/O pins will be grouped together.
Is this the correct way to create the symbol?
There are symbols availble on Github that do not follow this convention.
--
Regards,
Derek
