Stuff error( Bit timing parameters)

[chinna_indra2000]

Hi

I have used the following bit-timing settings on each board

Bit rate   = 1 Mbps
sync_seg   = 1
prop_seg   = 4
phase_seg1 = 5
phase_seg2 = 3
RJW        = 1
system clock frequencey = 56MHz
Baud rate= 83330

please let me know is this bit timing setting results in stuff error
and reply me with some configuration.

Regards,
Indrasena


RE: [MPC500] Stuff error


Stuff errors are hardware or timing related and there are no
restrictions on the content of the data frame - after 5 consecutive
bits
of ID, data or CRC, the Toucan will automatically stuff a bit. THe
only
s/w error is setting the bit timing.

Here are a few things to try:
- ensure you have the 120ohm termination resistors at each end of the
bus i.e. two 120 ohm resistors across CAN_H and CAN_L. THis is
essential.
- check or adjust your bit-timing settings and use the same settings
on
each device. THere's more to it than just having the numbers add up
to
the correct timing. Set RJW to max and make sure the prop delay is
reasonable. Look at the waveform on a scope to check the timing. With
the termination resistors, the waveform should look relatively
square.
- if it still doesn't work, try dropping the baud rate to see if you
get
any success. 1Mbaud is the max, but try reducing it just to see if
you
get any better success. If you have your bit-timings correct, 1M
should
be possible without errors.

- Allan

________________________________

From: MPC500@... [mailto:MPC500@...] On
Behalf
Of chinna_indra2000
Sent: Saturday, December 29, 2007 10:34 PM
To: MPC500@...
Subject: [MPC500] Stuff error



I get stuff error while transmitting messages over TouCAN.

Following is the test setup I have used for the CAN message
transmission Two MPC 565 boards connected by CAN cables (TouCAN A
and TouCAN B on one board connected to TouCAN A and TouCAN B
respectively on another board).

I have used Extended ID 0xEEEEEEEE for transmitting the Data Frame
from the first 565 board to second one.

When I send a message from First MPC565 board to the second one I
get a stuff error on second one.

Can a stuff error can occur due to problem in the software or does
it occur only due to hardware problem?

Is there any restriction on the content of the Data Frame ie., I
read in one of the CAN documents that there should not be 7
consecutive recessive bits in CAN frame.

Please let me know.

Regards,
Indrasena