Accessible pinout for MC68B21

Part description: Peripheral Interface Adapter 2MHz, DIP-40

Package description: This package has two parallel rows of pins extending down from opposite edges of the chip.

There should be a semicircular notch that you can feel in the middle of one of the package's shorter bare edges. With the pins facing downward and the chip oriented so notch is on the side of the chip furthest from you, Pin 1 will be in the far left corner of the chip.

Pins are numbered counter-clockwise. Numbers increase from the far left corner to the near left corner. They then continue on the right side, increasing from the near right corner to the far right corner. Thus the highest number pin is to the right of pin 1.

Pin assignments

Left side (numbering starts at far end)

Pin Signals
1VSS
2PA0
3PA1
4PA2
5PA3
6PA4
7PA5
8PA6
9PA7
10PB0
11PB1
12PB2
13PB3
14PB4
15PB5
16PB6
17PB7
18CB1
19CB2
20VCC

Right side (numbering starts at near end)

Pin Signals
21R / W (active low)
22CS0
23CS2 (active low)
24CS1
25ENABLE
26D7
27D6
28D5
29D4
30D3
31D2
32D1
33D0
34RESET (active low)
35RS1
36RS0
37IRQB (active low)
38IRQA (active low)
39CA2
40CA1

This pinout was automatically generated from the KiCAD symbol library revision 164574.

It is possible that there may be a mistake in the source data leading to wrong information on this page.