Serial Transmitters

[ludnough]

Hi,

A simple question. Are RSxxx transmitters and UARTS synonymous or are
they separate modules? If they're separate, what's the difference?

TIA

 

[hamilton]

You are getting your term confused.

ludnough wrote:

Hi,

A simple question.

Are RSxxx transmitters and UARTS synonymous or are
^^^^^

I think you mean RS-232 or RS-485 here. There are just voltage levels.
These voltage levels have nothing to do with the serial data stream,
so the serial stream can come from a bit banged micro, or a UART, or an
FPGA.

A UART is a hardware module inside a chip, or a standalone single chip
UART ( old technology).

The advent of the PC and people using the terms interchangeably has caused
all this confusion.

they separate modules? If they're separate, what's the difference?

TIA

 

[ludnough]

On Sat, 17 Jan 2004 09:38:57 -0700, hamilton wrote:

You are getting your term confused.

ludnough wrote:
Hi,

A simple question.

Are RSxxx transmitters and UARTS synonymous or are
^^^^^

I think you mean RS-232 or RS-485 here. There are just voltage levels.
These voltage levels have nothing to do with the serial data stream,
so the serial stream can come from a bit banged micro, or a UART, or an
FPGA.

A UART is a hardware module inside a chip, or a standalone single chip
UART ( old technology).

The advent of the PC and people using the terms interchangeably has caused
all this confusion.


they separate modules? If they're separate, what's the difference?

TIA

I was more concerned with the "transmitter" part of the term. I should
have clarified. On any note, I have seen the term "RS232 Transmitter"
used, but only once as a synonym for UART, and I have no other sources to
confirm if they are one and the same or not. Forgive me if I sound
boneheaded. I was wondering if the "RS232 Transmitter" and the the
transmitter portion of a UART are the same.

 

[Peter Bennett]

On Sat, 17 Jan 2004 01:11:12 -0600, ludnough <nobody@this.domain>
wrote:

Hi,

A simple question. Are RSxxx transmitters and UARTS synonymous or are
they separate modules? If they're separate, what's the difference?

TIA

They (if I read your question correctly) are very different devices.

A UART (Universal Asynchronous Receiver/Transmitter) does the
serial<->parallel conversion, and adds start and stop bits to the
transmitted data. The signal levels on the serial side are normally
TTL (0 and 5 volts).

An RS-232 line driver/receiver (such as a MAX232, MC1488/1489) is a
level shifter and inverter, to convert the TTL levels from the UART to
RS-232 levels (typically +/-12 volts or so), and convert from RS-232
to TTL levels.




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Peter Bennett, VE7CEI
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[hamilton]

ludnough wrote:

Forgive me if I sound
boneheaded. I was wondering if the "RS232 Transmitter" and the the
transmitter portion of a UART are the same.

For all intent and purpose, YES they are the same.

But this is an electronics group. So they are not the same.