General Purpose I/O Module
MCF5272 ColdFire Integrated Microprocessor User’s Manual, Rev. 3
17-2
Freescale Semiconductor
17.2
Port Control Registers
The port control registers are used to configure all pins that carry signals multiplexed from different
on-chip modules. Each pin is configured with a two-bit field. Pin functions are referred to as
function 0b00–0b11. The function 0 signals corresponding to GPIO ports A and B are immediately
available after reset.
Wherever a signal function includes a GPIO port bit, the function defaults to an input after a reset and can
be read in the corresponding port data register.
Pin functions are generally grouped logically. For example, all UART1 signals are multiplexed with port
B and have the control register function code of 0b01.
There is no port C control register. Port C is enabled when the 16-bit-wide external data bus mode is
selected at reset by the input level on QSPI_DOUT/WSEL. The port D control register is used to configure
pins that have multiple functions (0b01 through 0b11) but no GPIO function.
CAUTION
Do not attempt to program a pin function that is not defined. Where no
function is defined, the function code is labeled ‘Reserved’ and is
considered invalid. Programming any control register field with a reserved
value has an unpredictable effect on the corresponding pin’s operation.
Reserved function codes cannot be reliably read. Attempts to read them
yield undetermined values.
Table 17-2. GPIO Port Register Memory Map
MBAR
Offset
[31:24]
[23:16]
[15:8]
[7:0]
0x0080
Port A Control Register (PACNT)
0x0084
Port A Data Direction Register (PADDR)
Reserved
0x0086
Reserved
Port A Data Register (PADAT)
0x0088
Port B Control Register (PBCNT)
0x008C
Port B Data Direction Register (PBDDR)
Reserved
0x008E
Reserved
Port B Data Register (PBDAT)
0x0094
Port C Data Direction Register (PCDDR)
Reserved
0x0096
Reserved
Port C Data Register (PCDAT)
0x0098
Port D Control Register (PDCNT)