[ECOS] SH3 77x9SE01 bug
Fri Apr 25 19:41:00 GMT 2003
Rod Campbell wrote:
> While attempting to build support for the 7729R, I found what I think is
> a bug in the existing 77x9SE01 platform. I am using eCos V 2.0b1
> The setting for the oscillator control Divider2 divide-by-6 is
> incorrect. This causes an illegal FRQCR value to be built and you won't
> get a reliable boot up from reset (I could get the system to boot about
> 1 out of 25 times).
I believe you that this causes problems in your case, but if so, I would
be surprised this wasn't noticed when it was originally developed. I'm
pretty sure the ports we were using were very reliable. Is the setting
board specific and it was a slightly different board variant maybe? After
all the se77x9 platform HAL is meant to support the 7709RP01, 7709SE01 and
7729SE01 boards. Unfortunately I can't remember which (one, two or all) of
these the port was originally written for.
If you can persuade me your change is legitimate I'll make it :).
Unfortunately I don't have any hardware myself to corroborate, sorry. But
if you can check in the ref manuals for these boards to check that this
value is correct for all the boards then fair enough. If it's only correct
for some of the boards then we can look at making it configurable
depending on the board.
> Also, the SCIF2 serial port won't work (bad baud
> rate generation because of incorrect peripheral clock value).
> In /packages/hal/sh/sh3/v2_0b1/include/mod_regs_cpg.h
> For the V3 (last) group of conditional compilation statements,
> following the statement #elif (CYGHWR_HAL_SH_00C_DIVIDER_2 == 6)
> change from: # define CYGARC_REG_FRQCR_INIT_DIVIDER2 0x2002
> to: # define CYGARC_REG_FRQCR_INIT_DIVIDER2 0x2001
I'm slightly more inclined to believe you here because it's possible SCIF2
wasn't tested. But again, given what you wrote above, I think we should
check this applies to all the board variants first.
eCosCentric http://www.eCosCentric.com/ The eCos and RedBoot experts
--[ "You can complain because roses have thorns, or you ]--
--[ can rejoice because thorns have roses." -Lincoln ]-- Opinions==mine
Before posting, please read the FAQ: http://sources.redhat.com/fom/ecos
and search the list archive: http://sources.redhat.com/ml/ecos-discuss
More information about the Ecos-discuss