"OpenPIC versus EPIC" in MPC8240 !
Sarnath Kannan
sparc64 at rediffmail.com
Thu Nov 1 21:13:02 EST 2001
Dear reader,
I am trying to enable interrupts on the sandpoint X2
board hosting MPC8240, in Mode 1.
I decided to use OPenPIC code (openpic.c) for EPIC,
as the MPC8240 manual claims that EPIC is an OpenPIC standard. But I find some disparities between the way EPIC's registers are organised and the way OpenPIC data
structures are declared.( openpic_defs.h )
According the OpenPIC data structure,
"OpenPIC_Source" resides at offset 0x50000
whereas the EPIC ( section 11 of MPC8240 manual)
says the it resides at 0x50200 ( See page 11-5)
So, there is absolutely no gaurantee that
openPIC code would work for EPIC, Am i right ?
One more, If some1 could give me a clear picture
of interrupt routing on sandpoint board, it would
be very useful.
From what i read, I have understood the following
Please correct me if I am wrong.
1. The INTA ( used by Function 0 of Winbond -
PCI/ISA bridge) is connected to IRQ0 of EPIC.
2. The PCI interrupts (INTx) are connected to the
remaining PINs of EPIC in some order. ( I dont
know which order they are connected )
Any help would be appreciated. Meanwhile, I am
reading the sandpoint manual also..( This one, I add
inorder to avoid replies like "RTFM")
Thanks for any help guys
Sarnath
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
More information about the Linuxppc-embedded
mailing list