RE: SMC2

Grant,

Look in your PowerQuicc 860 User's Manual on page 34-9,

Their is a table which show the proper pbpar,pbdir setting to enable smc2 (I
think).  I don't know how to explain the pbodr setting right off the top of
my head.  But it is in pages close to this one.

Hope that helps,
Jason

-----Original Message-----
From: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of Grant
Carter
Sent: Wednesday, June 07, 2000 8:35 AM
To: linuxppc-embedded
Subject: SMC2

I have been looking at uart.c in the kernel and have come across
something that I cannot figure out. Perhaps I am just being stupid.
Perhaps someone can set me straight please.

The following code is taken fron uart.c and is used to set up either
both SMC2 and SMC1 pins or, in the #else, just set up SMC1's pins.

#if USE_SMC2
        cp->cp_pbpar |= 0x00000cc0;
        cp->cp_pbdir &= ~0x00000cc0;
        cp->cp_pbodr &= ~0x00000cc0;
#else
        /* This will only enable SMC1 if you want SMC2 for something
else.
        */
        cp->cp_pbpar |= 0x000000c0;
        cp->cp_pbdir &= ~0x000000c0;
        cp->cp_pbodr &= ~0x000000c0;
#endif

When I look at my manuals, I see no reference made to the bits 20 and 21
in pbpar, pbdir or pbodr. How does setting those bits enable the SMC2
pins? Those are located in Port A (PA8 and PA9)

I guess my point is why are the Port B registers being modified for SMC2
pins which are found in Port A?

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Hi

Sorry I forgot to mention that this was for an 823. I am told that those
bits are correct for the 860, as PB20/PB21 are SMRXD2/SMTXD2 of SMC2. I just
wasn;t sure how that code worked for the 823. The manual I am currently
using is the MPC823UM/D and have also looked at the preliminary manuals for
the 823e but with no further luck.

Regards
Grant

--
Grant Carter                              gcarter@eng.uct.ac.za
Department of Electrical Engineering      University of Cape Town
Tel: +27 (0)21 650-3467                   Fax: +27 (0)21 650-3465
                     "Coffee not found - operator halted!"

----- Original Message -----
From: "Wohlgemuth, Jason" <redacted>
To: "'Grant Carter'" <redacted>; "'linuxppc-embedded'"
[off-list ref]
Sent: Wednesday, June 07, 2000 4:19 PM
Subject: RE: SMC2

Grant,

Look in your PowerQuicc 860 User's Manual on page 34-9,

Their is a table which show the proper pbpar,pbdir setting to enable smc2

(I

think).  I don't know how to explain the pbodr setting right off the top

of

my head.  But it is in pages close to this one.

Hope that helps,
Jason

-----Original Message-----
From: owner-linuxppc-embedded@lists.linuxppc.org
[mailto:owner-linuxppc-embedded@lists.linuxppc.org]On Behalf Of Grant
Carter
Sent: Wednesday, June 07, 2000 8:35 AM
To: linuxppc-embedded
Subject: SMC2



Hi

I have been looking at uart.c in the kernel and have come across
something that I cannot figure out. Perhaps I am just being stupid.
Perhaps someone can set me straight please.

The following code is taken fron uart.c and is used to set up either
both SMC2 and SMC1 pins or, in the #else, just set up SMC1's pins.

#if USE_SMC2
        cp->cp_pbpar |= 0x00000cc0;
        cp->cp_pbdir &= ~0x00000cc0;
        cp->cp_pbodr &= ~0x00000cc0;
#else
        /* This will only enable SMC1 if you want SMC2 for something
else.
        */
        cp->cp_pbpar |= 0x000000c0;
        cp->cp_pbdir &= ~0x000000c0;
        cp->cp_pbodr &= ~0x000000c0;
#endif

When I look at my manuals, I see no reference made to the bits 20 and 21
in pbpar, pbdir or pbodr. How does setting those bits enable the SMC2
pins? Those are located in Port A (PA8 and PA9)

I guess my point is why are the Port B registers being modified for SMC2
pins which are found in Port A?

Many thanks
Grant

--
Grant Carter                              gcarter@eng.uct.ac.za
Department of Electrical Engineering      University of Cape Town
Tel: +27 (0)21 650-3467                   Fax: +27 (0)21 650-3465
                     "Coffee not found - operator halted!"

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/

Grant Carter wrote:

Sorry I forgot to mention that this was for an 823.

Ooops.  I guess I should read ahead......

To make SMC2 work on the 823/850 you need to set bits 8 and 9 in
port A papar, clear those bits in padir, and you probably want to
set bit 9 in paodr (it may not be necessary, but it is logically correct).
Everything else in the driver should be OK.


	-- Dan

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/