ST16C450IP40 datasheet(4/28 Pages) EXAR

4 / 28 page

ST16C450

Rev. 4.20

Symbol

Signal

Pin Description

type

Address-0 Select Bit Internal registers address selection.

Address-1 Select Bit Internal registers address selection.

Address-2 Select Bit Internal registers address selection.

IOR

Read data strobe. Its function is the same as -IOR (see -

IOR), except it is active high. Either an active -IOR or IOR

is required to transfer data from 16C450 to CPU during a

read operation.

CS0

Chip Select-0. Logical 1 on this pin provides the chip select-

0 function.

CS1

Chip Select-1. Logical 1 on this pin provides the chip select-

1 function.

-CS2

Chip Select -2. Logical 0 on this pin provides the chip select-

2 function.

IOW

Write data strobe. Its function is the same as -IOW (see -

IOW), but it acts as an active high input signal. Either -IOW

or IOW is required to transfer data from the CPU to

ST16C450 during a write operation.

-AS

Address Strobe. A logic 0 transition on -AS latches the state

of the chip selects and the register select bits, A0-A2. This

input is used when address and chip selects are not stable

for the duration of a read or write operation, i.e., a micropro-

cessor that needs to de-multiplex the address and data bits.

If not required, the -AS input can be permanently tied to a

logic 0 (it is edge triggered).

D0-D7

1-8

2-9

43-47

2-4

I/O

Data Bus (Bi-directional) - These pins are the eight bit, tri-

state data bus for transferring information to or from the

controlling CPU. D0 is the least significant bit and the first

data bit in a transmit or receive serial data stream.

GND

Pwr

Signal and Power Ground.

SYMBOL DESCRIPTION

ST16C450IP40 Datasheet(PDF) 4 Page - Exar Corporation

ST16C450IP40 Datasheet(HTML) 4 Page - Exar Corporation

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Datasheet Download

Link URL