MPC850: Ethernet on SCC3

Gunther Brau gunther.brau at
Wed Aug 23 00:31:36 EST 2000

Hello everyone,

Here my Service Request to MOTOROLA:
System description:
In our product we would like a Ethernet port at the SCC3-Channel
("SCC1"=USB; SCC2=IrDA). The appropriate control signals /CD3
("RENA"=PC4) and /CTS3 ("CLSN"=PC5) of the Transceiver
(LXT905/LevelOne) have to be configured with the the bits 6 and 7
in the Special option register PCSO ("MPC850 User's manual" page 34-15).

Problem/Solution description:
Register PCSO must be initialized however definitely with 0x0C00
(reserved bits 4 and 5 are set!), thus it does not come to a transfer error
("Carrier sense lost" = no RENA or CLSN signal) !

My question:
How can this be? Is in the "MPC850 User's manual" a misprint? I had expected
to configure the Register PCSO according to User's manual with 0x0300!
By the way: With this configuration and with a MPC860 the control signals
/CD4 and /CTS4 would be configured (but there is no SCC4 in MPC850).
It would be very grateful, if you could check this circumstances.

Here the answer from MOTOROLA DigitalDNA Help:
Dear Gunther Brau,

In reply to your Service Request SR 1-V7U2 (see details below):

It's UM errata on page 34-15, figure 24-14.  CD3 and CTS3 are PC 4 and PC5,
CD3 is Port C4 and CTS3 is Port C5.
(Ok, an exact question does not always result in an exact response....)

Hope, that will help someone.

Mit freundlichen Grüßen
       (Best regards)
       Gunther Brau

Transferzentrum Mikroelektronik, Göppingen

Dipl.-Ing. (FH) G. Brau
Entwicklung  (Development)

Robert-Bosch-Straße 1
D-73 037 Göppingen
Phone: +49 (0 71 61) 679 -212
Fax:   +49 (0 71 61) 679 -245
e-Mail: mailto:gunther.brau at
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