Accessible pinout for 16550

Part description: PC16550D, Universal Asynchronous Receiver/Transmitter with FIFOs, PDIP-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
1D0
2D1
3D2
4D3
5D4
6D5
7D6
8D7
9RCLK
10SIN
11SOUT
12CS0
13CS1
14CS2 (active low)
15BAUDOUT (active low)
16XIN
17XOUT
18WR (active low)
19WR
20GND

Right side (numbering starts at near end)

Pin Signals
21RD (active low)
22RD
23DDIS
24TXRDY (active low)
25ADS (active low)
26A2
27A1
28A0
29RXRDY (active low)
30INTR
31OUT2 (active low)
32RTS (active low)
33DTR (active low)
34OUT1 (active low)
35MR
36CTS (active low)
37DSR (active low)
38DCD (active low)
39RI (active low)
40VCC

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.