Now take a look at the MUXing for the control subsystem. If a pin is assigned to the Control subsystem then the C28x has free use of the pin, even in this case the C28x will not be able to control the pull up or the open drain enable/disable. These are M3 only operations even if the pin is assigned to the Control subsystem. The mapping of the peripherals is compatible to C2000 devices. The input to the control subsystem comes through an input qualification block, that is compatible with Delfino and Piccolo products. The input always goes to the data register, even if the GPIO is configured as a peripheral function. This way the data register can always be used to read the state of the pin. The C28x decides whether the pin is a GPIO function, in which case the user will be able to set, clear and toggle the pin, or whether it is assigned to one of the peripherals. A new feature on a Concerto device is the ability to map GPIO zero through sixty-three to ePWM trip inputs, capture unit inputs or external interrupt one through three.