Hello,
We intend to us the TUSB544 as a cable redriver in the custom alt mode, we do not intend to redrive Displayport OR USB but a custom Gbs link.
Our design currently sets up the device in GPIO mode and uses pull up / pull down resistors to configure the CTL/FLIP pins as "4 Channel Custom Alt Mode - No Flip": DIR1 = H, DIR0 = H, CTL1 = H, CTL0 = L, FLIP = L.
But, the note on the datasheet on page 19 states the following:
"After power-up (VCC from 0 V to 3.3 V), the TUSB544 will default to USB3.1 mode. The USB PD controller, upon detecting no device attached to Type-C port or USB3.1 operation not required by attached device, must take TUSB544 out of USB3.1 mode by transitioning the CTL0 pin from L to H and back to L."
This would imply we need to add some custom logic with delays to achieve this on CTL0? I cannot find the timing required for these transitions so if this is required could you please detail:
1. The LOW duration before the rising edge after power up
2. The duration of the high period before driving the CTRL0 pin low again?
Figure "7.4.8 Operation Timing - Power Up" on page 32 of the datasheet does not go into enough detail to show when these transition for CTL0 are required in GPIO mode .
Our design only contains this redriver part with a power supply, we do not want to add an MCU to set up this device to keep complexity and cost down.
Thanks
Gary
