mstechca
New Member
I have been looking at IC's for my microcontroller programmer design, and what makes me disgusted the most is the fact that the pin organization of most IC's SUCKS.
Here's what I mean.
Lets take a 74HC688 8-BIT magnitude comparator for example. It seems that on one side, the data must be connected in an interleaved fashion. In order words, bit 0 of byte 1 to pin 1, bit 0 of byte 2 to pin 1, bit 1 of byte 1 to pin 3, and so on.
But whoever made the 74HC245 was smart, because each byte can enter the chip at its own end. One side has one byte, the other side has the other byte. This is the property I would like to see in every chip.
Interleaving the bytes just makes it more difficult to create the PCB on a single-sided board.
but why do they interleave the bytes?
Here's what I mean.
Lets take a 74HC688 8-BIT magnitude comparator for example. It seems that on one side, the data must be connected in an interleaved fashion. In order words, bit 0 of byte 1 to pin 1, bit 0 of byte 2 to pin 1, bit 1 of byte 1 to pin 3, and so on.
But whoever made the 74HC245 was smart, because each byte can enter the chip at its own end. One side has one byte, the other side has the other byte. This is the property I would like to see in every chip.
Interleaving the bytes just makes it more difficult to create the PCB on a single-sided board.
but why do they interleave the bytes?