Reply by Michael Frazier●September 14, 20092009-09-14
On the LPC2468 the CRS and CRS_DV are the same pin as they both have a similar
function one is CARRIER SENSE for MII interface and the other is CARRIER
SENSE/DATA VALID for the RMII interface.
________________________________
From: l... [mailto:l...] On Behalf Of freudenbergerdavid
Sent: Thursday, September 10, 2009 1:33 PM
To: l...
Subject: [lpc2000] LPC2388 + Micrel KSZ8721 chip
Hello,
I'm working on a project based on a LPC2388 and a Micrel KSZ8721 chip. I
purchased a kit from Olimex (LPC2378 board) and I found out there was a mistake
on the schematic : the pin 22 (CRS) and the pin 9 (CRSDV) of the Micrel are
connected together on the board (a small wire below the chip has been added) but
it is not mentionned on the schematic...
Why these pins are connected together ? I don't know if it same on the
others designs from Olimex (LPC2468/78 for instance) but on the Keil board
(LPC23xx), the chip used is a Micrel too (almost the same chip) and both signals
are separated...
Reply by alexander_ribero●September 11, 20092009-09-11
Hi:
Additionally, these two pins are outputs from the PHY and should not be tied
together, to avoid damage of the internal drivers.
Regards,
Alex
--- In l..., "alexander_ribero" wrote: >
> Hi:
>
> Take a look at this message, and associated thread:
>
> http://tech.groups.yahoo.com/group/lpc2000/message/42731
>
> Regards,
>
> Alex
>
> --- In l..., "freudenbergerdavid" wrote:
> >
> > Hello,
> >
> > I'm working on a project based on a LPC2388 and a Micrel KSZ8721 chip.
I purchased a kit from Olimex (LPC2378 board) and I found out there was a
mistake on the schematic : the pin 22 (CRS) and the pin 9 (CRSDV) of the Micrel
are connected together on the board (a small wire below the chip has been added)
but it is not mentionned on the schematic...
> >
> > Why these pins are connected together ? I don't know if it same on the
others designs from Olimex (LPC2468/78 for instance) but on the Keil board
(LPC23xx), the chip used is a Micrel too (almost the same chip) and both signals
are separated...
> >
> > Any informations about this ?
> >
> > Thank you in advance !
> >
> > David
>
Reply by alexander_ribero●September 11, 20092009-09-11
Hi:
Take a look at this message, and associated thread:
--- In l..., "freudenbergerdavid" wrote: >
> Hello,
>
> I'm working on a project based on a LPC2388 and a Micrel KSZ8721 chip. I
purchased a kit from Olimex (LPC2378 board) and I found out there was a mistake
on the schematic : the pin 22 (CRS) and the pin 9 (CRSDV) of the Micrel are
connected together on the board (a small wire below the chip has been added) but
it is not mentionned on the schematic...
>
> Why these pins are connected together ? I don't know if it same on the
others designs from Olimex (LPC2468/78 for instance) but on the Keil board
(LPC23xx), the chip used is a Micrel too (almost the same chip) and both signals
are separated...
>
> Any informations about this ?
>
> Thank you in advance !
>
> David
>
Reply by freudenbergerdavid●September 10, 20092009-09-10
Hello,
I'm working on a project based on a LPC2388 and a Micrel KSZ8721 chip. I
purchased a kit from Olimex (LPC2378 board) and I found out there was a mistake
on the schematic : the pin 22 (CRS) and the pin 9 (CRSDV) of the Micrel are
connected together on the board (a small wire below the chip has been added) but
it is not mentionned on the schematic...
Why these pins are connected together ? I don't know if it same on the
others designs from Olimex (LPC2468/78 for instance) but on the Keil board
(LPC23xx), the chip used is a Micrel too (almost the same chip) and both signals
are separated...
