XC2200 Derivatives
System Units (Vol. 1 of 2)
Parallel Ports
User’s Manual
7-6
V2.1, 2008-08
Parallel Ports, V1.6D6
7.2
Port Register Description
7.2.1
Pad Driver Control
The pad 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.
In order to minimize EMI problems, the driver strength can be adapted to the application
requirements by bit fields PDMx. The selection is done in groups of four pins.
The
Port Output Control registers
POCON provide the corresponding control bits. A
4-bit control field configures the driver strength and the edge shape. Word ports
consume four control nibbles each, byte ports consume two control nibbles each, where
each control nibble controls 4 pins of the respective port.
Note: P2_POCON register in the
XC2200
contains an exception regarding the additional
strong output driver connected in parallel to the standard output driver of the P2.8
pin. See port 2 section.