17-10
MCF5272 User’s Manual
Data Direction Registers
the appropriate control register. If a GPIO line changes from an input to an output, the initial
data on that pin is the last data written to the latch by the corresponding data register.
At system reset, these register bits are all cleared, configuring all port I/O lines as general
purpose inputs. Bootstrap software must write an appropriate value into the data direction
register to configure GPIO port signals as outputs. When these registers are first written, any
internal pullups on the corresponding I/O pins are disabled.
A detailed description is provided only for data direction register A (PADDR). The control
bits in all three registers operate in the same manner.
17.3.1 Port A Data Direction Register (PADDR)
The PADDR determines the signal direction of each parallel port pin programmed as a
GPIO port in the PACNT.
17.3.2 Port B Data Direction Register (PBDDR)
The PBDDR determines the signal direction of each parallel port pin programmed as a
GPIO port in the PBCNT.
15
0
Field
PADDR
Reset
0000_0000_0000_0000
R/W
Read/Write
Addr
MBAR + 0x0084
Figure 17-4. Port A Data Direction Register (PADDR)
Table 17-9. PADDR Field Descriptions
Bits
Name
Description
15–0
PADDR
Data direction bits. Each data direction bit selects the direction of the signal as follows:
0 Signal is defined as an input.
1 Signal is defined as an output.
15
0
Field
PBDDR
Reset
0000_0000_0000_0000
R/W
Read/Write
Addr
MBAR + 0x008C
Figure 17-5. Port B Data Direction Register (PBDDR)
Содержание DigitalDNA ColdFire MCF5272
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Страница 90: ...2 42 MCF5272 User s Manual Exception Processing Overview ...
Страница 96: ...3 6 MCF5272 User s Manual MAC Instruction Execution Timings ...
Страница 158: ...5 46 MCF5272 User s Manual Motorola Recommended BDM Pinout ...
Страница 184: ...7 12 MCF5272 User s Manual Interrupt Controller Registers ...
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Страница 492: ...21 10 MCF5272 User s Manual Non IEEE 1149 1 Operation ...
Страница 548: ...INDEX Index 12 MCF5272 User s Manual ...