ARM940T & IPOD: cannot acess external memory

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1

Hello

I am trying to debug on a samsung S5l8701 (ipod nano2)

http://l4n.clustur.com/index.php/Nano2G%2BHW%2Banalysis

http://l4n.clustur.com/index.php/S5L8700_datasheet

The problem is, i cannot acess to all memories, the read values are most time fixed random patterns (last value exchanged ?)

could it be a problem from openocd to read mem at sys speed ?

also, there could be a protection inside the chip. I see the device freezing at the 2nd TCK clock !

my config :

if { [info exists CHIPNAME] } {
  set  _CHIPNAME $CHIPNAME
} else {
  set  _CHIPNAME arm
}
if { [info exists ENDIAN] } {
  set  _ENDIAN $ENDIAN
} else {
  set  _ENDIAN little
}
if { [info exists CPUTAPID ] } {
  set _CPUTAPID $CPUTAPID
} else {
 # force an error till we get a good number
  #set _CPUTAPID 0xffffffff
  set _CPUTAPID 0x10940f0f
}




#daemon configuration
telnet_port 54321
gdb_port 54320

#interface
interface parport
parport_port 0
parport_cable dlc5
jtag_speed 1

jtag_nsrst_delay 30


jtag newtap arm taptap  -irlen 4 -ircapture 0x1 -irmask 0xf
target create arm arm9tdmi -endian little -variant arm940t  -chain-position  0

reset_config trst_and_srst srst_pulls_trst

init
halt

poll off

source scripts.cfg
dc
poll

ic

armv4_5 reg

version : Open On-Chip Debugger 0.2.0-in-development (2009-06-17-21:48) svn:2268

I have no reset connection, i just catch the running processor (halting works good)

i suppose the 940T is not tested as well as the popular 920T, could there be a different pipeline timing, or other such subtile thing, corrupting the mem read?

what can i do ?