Микроконтроллер 8250
Date: Tue, 19 May 92 00:00:42 GMT
References: <7060318454537 @jaber.eecs.umich.edu> <1992may15 [email protected]> <1992may17 [email protected]>
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I just picked up a serial card with a 16550AFN UART chip. Is this the same as 16550A ? Also, will qmodem use the FIFO or do I need to install a fossil driver first? OR should i?
--
Brian Weaver [email protected] KD6CFA@N0ARY.#NOCAL.CA.USA.NA
From news-service Sun May 24 08:00:43 1992 To: subscribers
From: [email protected] (Scott C. Sadow) Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.ibm.pc.misc,comp.sys.ibm.pc.programmer Subject: [News] Re: UART information: 8250 vs 16450 vs 16550 vs 16550A Message-ID: <1992may20 [email protected]>
Date: Wed, 20 May 92 14:01:37 GMT
Article-I.D.: mycro.1992May20.100137
References:
Status: R
In article
>I just picked up a serial card with a 16550AFN UART chip. Is this
>the same as 16550A ?
Yes - a 16550AFN is a 16550A, and the "FN" suffix indicate something like plastic case and 40-pin dip package.
> Also, will qmodem use the FIFO or do I need
>to install a fossil driver first? OR should i?
I don't know the answer to this question.
Scott C. Sadow [email protected] ...gatech!nanovx!mycro!scott
From news-service Sun May 24 08:00:43 1992 To: subscribers
From: [email protected] (Scott C. Sadow) Newsgroups: comp.sys.ibm.pc.hardware,comp.sys.ibm.pc.misc,comp.sys.ibm.pc.programmer Subject: [News] Re: UART information: 8250 vs 16450 vs 16550 vs 16550A Message-ID: <1992may20 [email protected]>
Date: Wed, 20 May 92 14:03:51 GMT
Article-I.D.: mycro.1992May20.100351
References:
Status: R
In
article
>
> I have a question. What good does having an 8250 vs. 16450 vs.
> 16550 vs. 16550A. Why is the higher ones needed? What abilities
> does the 16550A have over teh 16550A or the 16550?
> Email or post. Thanks.
>
>Mortal@netcom
The 8250 is the original serial chip.
The 16450 is a newer version, but is essentially the same.
The 16550 was created to have internal FIFO queues for both transmit and receive, but the are bugs in the chip, so the manufacturer says not to use the FIFOs on that chip.
The 16550A is the same as a 16550A, but with working FIFOs.
The only real difference: If you have a 16550A and have software that can use the FIFOs, the chip will generate fewer interrupts. This means that the CPU has less to do to communicate at the same speeds, or can now communicate at higher speeds with the same CPU load.
Scott C. Sadow [email protected] ...gatech!nanovx!mycro!scott
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