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'Master' and 'slave': Tech terms face scrutiny amid anti-racism efforts
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tom66:

--- Quote from: dunkemhigh on June 21, 2020, 01:14:16 pm ---
--- Quote ---It's never clear whether TX on a schematic is the *transmit out*,  or *transmit signal in*.
--- End quote ---

It should always be out on a DTE (terminal), in on a DCE (modem).

If you have a problem with that then you'll also likely have a problem with the master/slave style too because you need to know which is the master and which the slave to work out what's in or out.

--- End quote ---

Master and slave is different, because it's clear that a master always initiates the transmission and the slave never does so.  It perfectly describes the arrangement.  An alternative description is "boss" and "worker" :-)

With TX and RX there have been ambiguous designs that I have reviewed by other engineers where the TX/RX on the connector is effectively reversed because it's matching the pinout of another connector.  Then having CPU_DATA_IN and CPU_DATA_OUT perhaps makes more sense but is a little wordy.  MISO and MOSI are considerably easier to understand.
Siwastaja:
MISO and MOSI are great names because they explicitly spell out the whole thing. MI and MO, or SO or SI would have been enough; or even worse, many others would have taken an assumed viewpoint (master, for example), like IBM did, allowing the wires to be just I and O - but Motorola thought, what the heck, let's be super explicit about it. I like that.

If you think about it, RX and TX are names that cannot be properly used between devices; they describe the device interface.

The IBM DTE/DCE nomenclature swaps the logic of naming when it comes to DCE, so now the device interface is misnamed, but this makes using "RX" and "TX" as names on the wires between devices, possible (with an implicit viewpoint of DTE). IMHO, this was a stupid decision.

I have not seen this elsewhere; for example, all microcontroller UART interfaces specify TX and RX in a way so they are out and in, respectively. This way, you don't need to configure the interface to be "DTE" or "DCE", but you need to connect TX to RX, and RX to TX (which is, obviously, highly logical and causes less confusion than the IBM's "sometimes connect TX to TX and RX to RX and sometimes connect TX to RX and RX to TX" logic). Some modern UART peripherals do have a mode of swapping TX and RX, but that seems to be to address for design mistakes without requiring PCB respins; because of the confusion initiated by IBM. SPI interfaces do not have such swapping features because mistakes are very rare thanks to highly logical and explicit naming.
vodka:



--- Quote from: Zero999 on June 20, 2020, 05:58:05 pm ---superficial differences such as skin colour don't matter

--- End quote ---

This is a textbook example of unconscious bias. Do you know why the police are more likely to stop and search (or kill in attempted self defense) certain ethnicities over others? Not because they are racist dickheads who read 4chan in their spare time, but precisely because some statistician somewhere had said that those races are more likely to commit crime. Or, dunno, ever heard of the concept of "white flight"? Pretty much what you have done, in different circumstances.



[/quote]

The policemen don't need to read 4chan for being informed , they are living themselves each day. And like said Lenin: the facts are stubborn .


--- Quote ---Truly liberal countries like Sweden at least made a good call and banned collection of any racial statistics whatsoever. If race doesn't exist than the risk of carrying corona can't be broken down by race. I can appreciate the honesty and integrity in that.
--- End quote ---

 :-DD :-DD :-DD :-DD They are more zones NO-GO, the rape rate more higher of europe and the far-right is growing in each election. These symptoms are a country what don't work fine


PlainName:

--- Quote ---so that you have to know the role (DTE vs. DCE) of the devices; only after that you can "simply" connect wires with same names together; and connecting DTE to DTE requires a special "crossover cable"
--- End quote ---

Exactly the same with MOSI. You have to know if that bit of kit is a receiver or transmitter, master or slave, sender or consumer, and then you know which way a particular pin is going. Any confusion is merely that you don't know what kind of device you're connecting to.

Your beef is actually that the higher-level protocol labeling doesn't lend itself to describing the low-level pin characteristics. Well, duh. Use a different - low-level - label, is the answer. It's surely not too hard to put "DataOut" or "DataIn" on the chip pin and "Serial Tx" on the schematic net.
PlainName:

--- Quote ---MISO and MOSI are great names because they explicitly spell out the whole thing.
--- End quote ---

You need to know whether a device is a master or slave, no? And when a microcontroller can be a master and slave, what is the pin function with the label MISO?
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