4 ms·
Yes, consecutive pins are often related in some way. Let say pin 3,4,5 and 6 belong to the same port, and must be connected to a connector on the other side of
by bnegreve 6y ago
Yes, consecutive pins are often related in some way. Let say pin 3,4,5 and 6 belong to the same port, and must be connected to a connector on the other side of the PCB.
If pins were numbered by columns, you would have to connect two tracks to one end of the chip and two other tracks to the other end of the chip. Once you've done that, routing the remaining tracks is basically impossible on a single PCB layer.
- bnegreve 6y agoIn other words, the standard numbering has the nice property that two pins with a consecutive id number are always relatively close to eachother (whatever the package).
- thedufer 6y ago> If pins were numbered by columns, you would have to connect two tracks to one end of the chip and two other tracks to the other end of the chip. You have missed my point entirely. All you have to do is re-label them. There is absolutely no re-wiring or re-routing implied by changing the pin numbers.
- bnegreve 6y agoNo I haven't, but I've failed to convince you, it seems. It does make a difference because the chip designer doesn't know or doesn't care how the chip is going to be packaged and where the pins are going to be placed on the package. With the standard numbering, two consecutive pins are always placed next to eachother no matter the package, and the chip designer can use this information to optimize the placement of related pins. This is not true with the alternative numbering "by column", where pin 4 and 5 are close on most packages, but far away on a DIP 8 package.