Chapter 4 Port Integration Module (S12XDP512PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
200 Freescale Semiconductor
Table 4-7. DDRB Field Descriptions
Field Description
7–0
DDRB[7:0]
Data Direction Port B — This register controls the data direction for port B. When Port B is operating as a general
purpose I/O port, DDRB determines whether each pin is an input or output. A logic level “1” causes the
associated port pin to be an output and a logic level “0” causes the associated pin to be a high-impedance input.
0 Associated pin is configured as input.
1 Associated pin is configured as output.
Note: Due to internal synchronization circuits, it can take up to 2 bus clock cycles until the correct value is read
on PORTB after changing the DDRB register.