in the last few weeks i followed some postings & tried to find out some facts about the sharp I/O connector on C1000/C3x00 devices (the port covered behind the plastic shield on the back). This led to some confusion .
So perhaps we might clear this up and collect some facts about this port, that's why i started this post.
You can find the specs of the I/O connector in this forum. It was released from sharp in 2001 and covers the SL-5000.
There are also some posts with a link to a document on hrw site where JTAG access for collie is mentioned (see link below).
All in all, these technical informations seem not to be completely valid for the latest C1000/3x00 devices.
Many of you reported that the serial lines are still available on the I/O connector of the C1000/3x00, because the standard sharp serial cable (C170) is still working with the C1000 as well as with the C3x00 devices. Another guy used it with a homemade cable as serial console output and had success.
I personally use a C3100 and did some measurements on the dedicated pins looking into the old spec from sharp.
The signals made sense to me, so i also assumed that the serial port is still there.
For now it is not completely tested by myself, but one may assume that pin 3-7 and pin 14 still carry the serial lines of ttyS0 (there's still some uncertainty about the handshake lines, i'd like to check this more intensely).
The behaviour of these pins may be identical to the SL-5000 spec.
So for the moment this could be taken as confirmed on C1000/3x00 devices!
Trisoft brought the JTAG thing on I/O into this forum.
At least in one of their famous documents JTAG is mentioned as service port available on I/O connector.
After having a closer look in the schematic published by hrw i thought it might be there as a secondary function of some of the serial lines.
Have a look at pin 13 (mentioned as reserved pull-down in SL-5000 spec), it is connected to VCC. Maybe there's a gate beeing activated through this pin which gives access to the JTAG lines of the cpu. At least on collie this should work.
This has to be checked for C1000/3x00!
Let's go further on!
How about the USB pins of the traditional I/O connector pinout (SL-5000 spec) on C1000/3x00?
No one mentioned a working USB connection using the USB pins on I/O connector.
Perhaps there's another USB host port waiting for connection.
As far as i remember albertr made some investigations concering additional USB inside C1000 (great page!!). The I/O connector is not discussed there.
I tried to connect a host PC as well as a memory stick with external power supply.
No success so far, but this has to be checked more extensely.
So the function of pins 9&12 of the connector is unsure (at least for me !)
Excluded on the C1000/3x00 I/O connector are pins 1,2 and 15,16. These were told not to be connected internally (formerly used as power input). This also seems correct.
The last thing is tested as well:
Pin 11 (VCC3) and Pin 8 (GND) deliver 3.3V power. These pins are allways under power. I don't think it can be switched without additional hardware.
Discussions are welcome!