Hi,
we are using the TUSB320 evaluation board and everything seems to
work fine when we connect the devboard to a laptop or to a Type-C
power adapter. The CURRENT_MODE_DETECT (i2c register 0x08) and
the ATTACHED_STATE (i2c register 0x09) are correctly updated.
However, we are having issues when connecting a debug accessory
to the evaluation board, in this case the TUSB320 doesn't appear to
properly recognize the debug accessory (see test 3) and 6) below).
In particular, these are the values read from the TUSB320 i2c registers
in the different test cases:
1) TUSB320 EVM (DRP: 1.7 OFF, 1.8 OFF) connected to a laptop
0x08 => 0x10 (current medium)
0x09 => 0x90 Attached.SNK (UFP)
2) TUSB320 EVM (DRP: 1.7 OFF, 1.8 OFF) connected to a Type-C power adapter
0x08 => 0x30 (current high)
0x09 => 0x90 Attached.SNK (UFP)
3) TUSB320 EVM (DRP: 1.7 OFF, 1.8 OFF) connected to debug accessory
0x08 => 0x00 (default - no debug accessory connected)
0x09 => 0x20 (not attached)
4) TUSB320 EVM (UFP: 1.7 OFF, 1.8 ON) connected to a laptop
0x08 => 0x30 (current high)
0x09 => 0xB0 Attached.SNK (UFP)
5) TUSB320 EVM (UFP: 1.7 OFF, 1.8 ON) connected to a Type-C power adapter
0x08 => 0x30 (current high)
0x09 => 0xB0 Attached.SNK (UFP)
6) TUSB320 EVM (UFP: 1.7 OFF, 1.8 ON) connected to debug accessory
0x08 => 0x00 (default - no debug accessory connected)
0x09 => 0x20 (not attached)
Please note that an I2C soft reset (writing 0b00001000 to register 0x0A)
doesn't change the results.
The same tests have been performed with or without external power to
the evaluation board, in both cases the detection of the debug accessory
doesn't work.
The debug accessory has two 56K pull-up resistors on CC (pins A5 and B5 Type-C connector)
and it is properly recognised with other Type-C chips.
Regards
