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Discussion - Hardware / FT4232H What controls the PWREN# pin
« on: March 25, 2022, 01:28:58 PM »
We are using a FT4232H USB to serial bridge in one of out boards. We are using it in MPSSE mode. We would like to let some logic drive switches to disconnect the I2C and SPI buses connected to the FT4232H when the device is not in use.
I see that the PWREN# pin may be used for this purpose. As I can see from the datasheet and application notes, the PWREN# pin is low when the device has been configured by the USB host.
What exactly does it mean that the device has been configured? Does it mean that power has been enabled and no command has been sent over USB? Is it the time between power-on/reset and the initial USB communication or configuration commands? As i understand the device will start up in UART mode. Is this state considered to be configured?
Anyone have some insight into the distinctions here?
I see that the pin changes state in USB suspend mode. This is not so interesting for this application. I would like PWREN# to go low when MPSSE mode has been initiated.
I see that the PWREN# pin may be used for this purpose. As I can see from the datasheet and application notes, the PWREN# pin is low when the device has been configured by the USB host.
What exactly does it mean that the device has been configured? Does it mean that power has been enabled and no command has been sent over USB? Is it the time between power-on/reset and the initial USB communication or configuration commands? As i understand the device will start up in UART mode. Is this state considered to be configured?
Anyone have some insight into the distinctions here?
I see that the pin changes state in USB suspend mode. This is not so interesting for this application. I would like PWREN# to go low when MPSSE mode has been initiated.