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Discussion - Drivers / Re: I2C lockup/hang and "bus clear" using FT4222 Windows API? (I2C spec 3.1.16)
« on: August 30, 2019, 03:11:43 PM »
FTDI support suggests “FT4222_ChipReset”. I will investigate and report my findings.
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Which version of LibFT4222 are you using? Which version of the D2XX driver are you using?
The latest are v1.4.2 and 2.12.28 respectively (for Windows).
Which FT4222H IC revision are you using?
Have you tested out the I2C examples provided with LibFT4222?
sizeTransferred = 0;
ft42Status = FT4222_I2CMaster_Write(FTDIHandle, slaveAddress, writeBuf, (ushort)sizeToWrite, &sizeTransferred);
Writing 7 bytes...
11 SENT: aa 00 06 00 02 4e ff
3.1.16 Bus clear
In the unlikely event where the clock (SCL) is stuck LOW, the preferential procedure is to
reset the bus using the HW reset signal if your I2C devices have HW reset inputs. If the
I2C devices do not have HW reset inputs, cycle power to the devices to activate the
mandatory internal Power-On Reset (POR) circuit.
If the data line (SDA) is stuck LOW, the master should send nine clock pulses. The device
that held the bus LOW should release it sometime within those nine clocks. If not, then
use the HW reset or cycle power to clear the bus.