_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
Hawk777 has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
nerozero has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
zjason` is now known as zjason
zjason` has joined #openocd
zjason has quit [Ping timeout: 252 seconds]
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
Hawk777 has quit [Quit: Leaving.]
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
_whitelogger_ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
<Hammdist>
yesterday I asked about the possibility of JTAG daisy chain, and it turned out OpenOCD supported it. now I'm thinking great, but what about performance? will the performance be degraded with multiple devices?
<Hammdist>
iow are command packets long and target a specific device so firmware can be uploaded at close to full speed, or does the protocol peel bits off one at a time and so performance is halved for two devices, thirded for three devices, etc
<clever>
Hammdist: on the one side of things, every write to IR will have to go thru the full length of the combined IR registers
<clever>
as an example, the jtag arm debug port on the rpi's, has a 4bit IR
<clever>
if i was to string 4 pi's into a daisy chain, it would now take 16 clocks to put any command into the IR register
<clever>
then on the DR side, there is a dedicated BYPASS register, so un-addresses devices only add 1 clock of overhead
<clever>
but i'm unsure how you would address all of the devices at once, that would get complicated
<clever>
for the arm debug specifically, i think a large chunk of the access could be done exclusively with IR=APACC, APSEL=0, and APBANKSEL=0
<clever>
so once youve initialized things, you can just ignore IR and shift a 35bit code into each device on every bus transaction
<clever>
and with 4 pi's daisy chained together, thats just a 140bit code, containing all 35bit codes concat'd
<Hammdist>
so post-initialization there is no slowdown for uploading e.g. firmware to an stm32
<clever>
i'm unsure how the stm32 works there
<clever>
i can imagine how you might upload the firmware to a dozen stm32's at once, if you just duplicate the data a dozen times, and check all of the status codes
<clever>
but i'm not sure how much time it would save, vs just getting a dozen jtag adapters?
<clever>
if they are all in the same state, its a bit simpler, vs the arm debug stuff where they are in wildly different states
<Hammdist>
I don't want to parallelize my question is mainly whether it will run "full speed" to upload firmware despite the other devices being on the chain
<clever>
ah, so your thinking of the stm32 plus something else, on the same chain, and wanting to access one of them
<Hammdist>
basically yeah
<clever>
for updating the IR register, the cost will scale with the number of devices and the size of the IR's, so it could harm performance, but i suspect IR isnt updated much?
<clever>
i think you would need to start by just daisy-chaining things, and getting some logs with `-d4`, and then somebody could look over it and see
<Hammdist>
well my question is mainly theoretical. I will be daisy chaining 2 devices only for now so I can tolerate 2:1 slowdown but it would be nice to know it won't be that way
<clever>
in the case of arm debug, once init is done, the IR is never updated
<clever>
so that cost goes away
<clever>
and then your only paying 1bit of overhead for each non-addressed device
<clever>
so a 35bit transfer with 3 dead devices in the chain, would only cost you 38bits of time
<clever>
so it would run at about 92% speed, roughly
<Hammdist>
I see
<clever>
id need to know more about stm32 upload, to give any solid answers
jmi2k has joined #openocd
_whitelogger__ has joined #openocd
_whitelogger_ has quit [*.net *.split]
JakeSays has quit [*.net *.split]
merethan has quit [*.net *.split]
crabbedhaloablut has quit [*.net *.split]
dliviu has quit [*.net *.split]
noarb has quit [*.net *.split]
pengi has quit [*.net *.split]
antto has quit [*.net *.split]
ChanServ has quit [*.net *.split]
Getty has quit [Quit: Ping timeout (120 seconds)]
Getty3 has joined #openocd
Getty3 is now known as Getty
JakeSays has joined #openocd
merethan has joined #openocd
crabbedhaloablut has joined #openocd
dliviu has joined #openocd
antto has joined #openocd
pengi has joined #openocd
noarb has joined #openocd
ChanServ has joined #openocd
JakeSays has quit [*.net *.split]
merethan has quit [*.net *.split]
crabbedhaloablut has quit [*.net *.split]
dliviu has quit [*.net *.split]
noarb has quit [*.net *.split]
pengi has quit [*.net *.split]
antto has quit [*.net *.split]
ChanServ has quit [*.net *.split]
jmi2k has quit [*.net *.split]
WeaselSoup has quit [*.net *.split]
Xogium has quit [*.net *.split]
wmat has quit [*.net *.split]
zmatt has quit [*.net *.split]
dnm has quit [*.net *.split]
icee has quit [*.net *.split]
_whitelogger__ has quit [*.net *.split]
zjason` has quit [*.net *.split]
diddly has quit [*.net *.split]
tsal has quit [*.net *.split]
Bertl has quit [*.net *.split]
braunr has quit [*.net *.split]
HumanG33k has quit [*.net *.split]
clever has quit [*.net *.split]
van has quit [*.net *.split]
ericonr has quit [*.net *.split]
juri_ has quit [*.net *.split]
Getty has quit [*.net *.split]
dormito has quit [*.net *.split]
marex has quit [*.net *.split]
polprog has quit [*.net *.split]
jn has quit [*.net *.split]
renrelkha has quit [*.net *.split]
Yamakaja_ has quit [*.net *.split]
geep has quit [*.net *.split]
zkrx has quit [*.net *.split]
manawyrm has quit [*.net *.split]
phr3ak has quit [*.net *.split]
nerozero has quit [*.net *.split]
gamiee has quit [*.net *.split]
sys64738 has quit [*.net *.split]
zear has quit [*.net *.split]
sugarbeet has quit [*.net *.split]
PaulFertser has quit [*.net *.split]
flatmush has quit [*.net *.split]
Dracos-Carazza has quit [*.net *.split]
rkta has quit [*.net *.split]
urja has quit [*.net *.split]
nathanhi has quit [*.net *.split]
bencoh has quit [*.net *.split]
mawk has quit [*.net *.split]
sbach has quit [*.net *.split]
vampirefrog has quit [*.net *.split]
a3f has quit [*.net *.split]
shoragan has quit [*.net *.split]
HelloShitty has quit [*.net *.split]
gruetzkopf has quit [*.net *.split]
key2 has quit [*.net *.split]
ringo has quit [*.net *.split]
Fleck has quit [*.net *.split]
lh has quit [*.net *.split]
bryanb has quit [*.net *.split]
Hammdist has quit [*.net *.split]
bacam has quit [*.net *.split]
karlp has quit [*.net *.split]
xphn has quit [*.net *.split]
drath42 has quit [*.net *.split]
mrec has quit [*.net *.split]
stefanct has quit [*.net *.split]
haxar has quit [*.net *.split]
Getty has joined #openocd
haxar has joined #openocd
drath42 has joined #openocd
Fleck has joined #openocd
xphn has joined #openocd
zear has joined #openocd
polprog has joined #openocd
ringo has joined #openocd
karlp has joined #openocd
sys64738 has joined #openocd
phr3ak has joined #openocd
marex has joined #openocd
zkrx has joined #openocd
juri_ has joined #openocd
gruetzkopf has joined #openocd
key2 has joined #openocd
manawyrm has joined #openocd
ericonr has joined #openocd
HelloShitty has joined #openocd
van has joined #openocd
stefanct has joined #openocd
gamiee has joined #openocd
geep has joined #openocd
bacam has joined #openocd
dormito has joined #openocd
clever has joined #openocd
wmat has joined #openocd
zmatt has joined #openocd
bryanb has joined #openocd
dnm has joined #openocd
icee has joined #openocd
Yamakaja_ has joined #openocd
PaulFertser has joined #openocd
lh has joined #openocd
shoragan has joined #openocd
HumanG33k has joined #openocd
braunr has joined #openocd
Hammdist has joined #openocd
a3f has joined #openocd
renrelkha has joined #openocd
vampirefrog has joined #openocd
mrec has joined #openocd
Bertl has joined #openocd
jn has joined #openocd
sugarbeet has joined #openocd
tsal has joined #openocd
sbach has joined #openocd
nerozero has joined #openocd
diddly has joined #openocd
zjason` has joined #openocd
jmi2k has joined #openocd
_whitelogger__ has joined #openocd
JakeSays has joined #openocd
merethan has joined #openocd
dliviu has joined #openocd
crabbedhaloablut has joined #openocd
antto has joined #openocd
pengi has joined #openocd
ChanServ has joined #openocd
noarb has joined #openocd
KindOne has quit [Max SendQ exceeded]
jn has quit [*.net *.split]
renrelkha has quit [*.net *.split]
Yamakaja_ has quit [*.net *.split]
geep has quit [*.net *.split]
zkrx has quit [*.net *.split]
manawyrm has quit [*.net *.split]
phr3ak has quit [*.net *.split]
jn has joined #openocd
renrelkha has joined #openocd
Yamakaja_ has joined #openocd
geep has joined #openocd
manawyrm has joined #openocd
zkrx has joined #openocd
phr3ak has joined #openocd
KindOne has joined #openocd
WeaselSoup has joined #openocd
Xogium has joined #openocd
cp- has quit [Ping timeout: 249 seconds]
sbach has quit [*.net *.split]
vampirefrog has quit [*.net *.split]
a3f has quit [*.net *.split]
shoragan has quit [*.net *.split]
HelloShitty has quit [*.net *.split]
gruetzkopf has quit [*.net *.split]
key2 has quit [*.net *.split]
ringo has quit [*.net *.split]
Fleck has quit [*.net *.split]
mawk` has joined #openocd
cp- has joined #openocd
sbach has joined #openocd
gruetzkopf has joined #openocd
HelloShitty has joined #openocd
shoragan has joined #openocd
vampirefrog has joined #openocd
key2 has joined #openocd
ringo has joined #openocd
Fleck has joined #openocd
a3f has joined #openocd
flatmush has joined #openocd
rkta has joined #openocd
Dracos-Carazza has joined #openocd
urja has joined #openocd
nathanhi has joined #openocd
bencoh has joined #openocd
mawk has joined #openocd
mawk has quit [Max SendQ exceeded]
lh has quit [*.net *.split]
bryanb has quit [*.net *.split]
Hammdist has quit [*.net *.split]
bacam has quit [*.net *.split]
karlp has quit [*.net *.split]
xphn has quit [*.net *.split]
drath42 has quit [*.net *.split]
karlp has joined #openocd
bryanb has joined #openocd
lh has joined #openocd
bacam has joined #openocd
drath42 has joined #openocd
xphn has joined #openocd
Hammdist has joined #openocd
jmi2k has quit [*.net *.split]
jmi2k has joined #openocd
KindOne has quit [*.net *.split]
sugarbeet has quit [*.net *.split]
PaulFertser has quit [*.net *.split]
mawk` is now known as mawk
KindOne has joined #openocd
PaulFertser has joined #openocd
sugarbeet has joined #openocd
nerozero has quit [*.net *.split]
gamiee has quit [*.net *.split]
sys64738 has quit [*.net *.split]
zear has quit [*.net *.split]
KindOne has quit [Max SendQ exceeded]
KindOne has joined #openocd
nerozero has joined #openocd
gamiee has joined #openocd
sys64738 has joined #openocd
zear has joined #openocd
wmat has quit [*.net *.split]
zmatt has quit [*.net *.split]
dnm has quit [*.net *.split]
icee has quit [*.net *.split]
wmat has joined #openocd
dnm has joined #openocd
zmatt has joined #openocd
icee has joined #openocd
mrec has quit [*.net *.split]
stefanct has quit [*.net *.split]
haxar has quit [*.net *.split]
mrec has joined #openocd
stefanct has joined #openocd
haxar has joined #openocd
Getty has quit [*.net *.split]
dormito has quit [*.net *.split]
marex has quit [*.net *.split]
polprog has quit [*.net *.split]
Getty has joined #openocd
dormito has joined #openocd
polprog has joined #openocd
marex has joined #openocd
_whitelogger__ has quit [*.net *.split]
zjason` has quit [*.net *.split]
diddly has quit [*.net *.split]
tsal has quit [*.net *.split]
Bertl has quit [*.net *.split]
braunr has quit [*.net *.split]
HumanG33k has quit [*.net *.split]
clever has quit [*.net *.split]
van has quit [*.net *.split]
ericonr has quit [*.net *.split]
juri_ has quit [*.net *.split]
juri_ has joined #openocd
tsal has joined #openocd
Bertl has joined #openocd
braunr has joined #openocd
HumanG33k has joined #openocd
zjason` has joined #openocd
clever has joined #openocd
van has joined #openocd
ericonr has joined #openocd
diddly has joined #openocd
_whitelogger__ has joined #openocd
HumanG33k has quit [Max SendQ exceeded]
HumanG33k has joined #openocd
_whitelogger__ has quit [Remote host closed the connection]
_whitelogger_ has joined #openocd
nerozero has quit [Ping timeout: 246 seconds]
jmi2k has quit [Quit: Client closed]
uartist has quit [Quit: Ping timeout (120 seconds)]
uartist has joined #openocd
borneoa___ has quit [Quit: Connection closed for inactivity]