Subject: Re: High serial port (output) speeds
To: Todd Whitesel <>
From: Hauke Fath <hauke@Espresso.Rhein-Neckar.DE>
List: port-sparc
Date: 10/23/1999 19:26:07
At 1:04 Uhr +0200 23.10.1999, Todd Whitesel wrote:

>The main advantage you get from deliberately using X16 mode is that the
>input logic can use the extra ticks to clean up an input signal by taking
>multiple samples and integrating them -- at least one motorola serial chip
>(68681?) does this, but I no longer recall offhand if the 8530 did it too.

According to a Zilog data book that I have lying here, this appears to be
not an issue for the 8530.

... Reception is protected from spikes by a transient spike-rejection
mechanism that checks the signal one-half a bit time after a Low level is
detected on the receive data input (RxDA or RxDB in Figure 1). If the Low
does not persist (as in the case of a transient), the character assembly
process does not start.
The transmitter and receiver can handle data at a rate of 1, 1/16, 1/32 and
1/64 of the clock rate supplied to the receive and transmit clock inputs.

I.e., no limitation is mentioned anywhere for using X1 mode.


"It's never straight up and down"     (DEVO)