C515C Datasheet, PDF (32/69 Pages) Siemens Semiconductor Group – 8-Bit CMOS Microcontroller

C515C
Port Structure Selection of Port 5
After a reset operation of the C515C, the quasi-bidirectional 8051-compatible port structure is
selected. For selection of the bidirectional (CMOS) port 5 structure the bit PMOD of SFR SYSCON
must be set. Because each port 5 pin can be programmed as an input or an output, additionally,
after the selection of the bidirectional mode the direction register DIR5 of port 5 must be written.
This direction register is mapped to the port 5 register. This means, the port register address is
equal to its direction register address. Figure 10 illustrates the port- and direction register
configuration.
Figure 10
Port Register, Direction Register
Semiconductor Group
32
1997-07-01