User Manual
382
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
GPIO Ports and Peripheral I/O
15.2.1
Port 0 and Port 1
shows the block diagram of an TLE984xQX bidirectional port pin. Each port pin is equipped with a
number of control and data bits, thus enabling very flexible usage of the pin. By defining the contents of the
control register, each individual pin can be configured as an input or an output. The user can also configure
each pin as an open drain pin with or without internal pull-up/pull-down device.
Each bidirectional port pin can be configured for input or output operation. Switching between input and
output mode is accomplished through the register Px_DIR (x = 0 or 1), which enables or disables the output
and input drivers. A port pin can only be configured as either input or output mode at any one time.
In input mode (default after reset), the output driver is switched off (high-impedance). The actual voltage level
present at the port pin is translated into a logic 0 or 1 via a Schmitt-Trigger device and can be read via the
register Px_DATA.
In output mode, the output driver is activated and drives the value supplied through the multiplexer to the
port pin. In the output driver, each port line can be switched to open drain mode or normal mode (push-pull
mode) via the register Px_OD.
The output multiplexer in front of the output driver enables the port output function to be used for different
purposes. If the pin is used for general purpose output, the multiplexer is switched by software to the data
register Px_DATA. Software can set or clear the bit in Px_DATA and therefore directly influence the state of the
port pin. If an on-chip peripheral uses the pin for output signals, alternate output lines (AltDataOut) can be
switched via the multiplexer to the output driver circuitry. Selection of the alternate function is defined in
registers Px_ALTSEL0 and Px_ALTSEL1. When a port pin is used as an alternate function, its direction must be
set accordingly in the register Px_DIR.
Each pin can also be programmed to activate an internal weak pull-up or pull-down device. Register
Px_PUDSEL selects whether a pull-up or the pull-down device is activated while register Px_PUDEN enables
or disables the pull device.
The port structure used in this device offers the possibility to select the output driver strength and the slew
rate. These selections are independent from the output port functionality, such as open-drain, push/pull or
input only. The driver strength for each pin can be adapted to the application requirements by registers
Px_POCONy (y = 0, 1 or 2) in SCU_DM.
The temperature compensation signals TC[1:0] of all output drivers are connected to all outputs and are
controlled by register SCU_TCCR.TC[1:0] in SCU_DM.
Note:
For the definition of Px_POCONy and TCCR registers, refer to
of SCU_DM chapter.