29.6.2.1 Mailbox

The mailbox (4 Kbytes) is used to indicate to the pPP the X and Y topoloy as well as the number of sensors implemented.

The mailbox can also be used, for example, to pass the parameters required by an application to adjust the analog or digital gain, the filtering functions and some touch operation timing values.

The mailbox is the main way to control the PTC digital and analog components. The pPP firmware reads the mailbox and performs the tasks requested. After execution, some data are fed back to the mailbox to be read by the main processor, such as touch button confirmation or touch position on the slider or wheel.