Motorola MPC860 PowerQUICC, User Manual

Page: 886 / 1106

34-4 MPC860 PowerQUICC UserÕs Manual MOTOROLA
Part V. The Communications Processor Module
Table 34-2 describes PAODR bits.
34.2.1.2 Port A Data Register (PADAT)
Reading the port A data (PADAT) register returns the value of the signal, regardless of
whether the signal is an input or output. Comparing written data with the data on the signal
can detect output conßicts. A write to a PADAT bit is latched; if the bit is conÞgured as an
output, the value latched for that bit is driven onto its respective signal. PADAT can be read
or written at any time, is not initialized, and is undeÞned at reset.
Table 34-3 describes PADAT bits.
34.2.1.3 Port A Data Direction Register (PADIR)
Port A data direction register (PADIR) bits conÞgure port A signals as general-purpose
inputs or outputs. If a signal is not programmed for general-purpose I/O, PADIR selects the
peripheral function to be performed.
Table 34-2. PAODR Bit Descriptions
Bits Name Description
0Ð7, 13,
15 Ñ Reserved, always reads as 0.
8Ð12, 14 OD n Tells how the corresponding port A signal is interpreted.
0 The signal is actively driven as an output.
1 The signal is an open-drain driver. Outputs are actively driven low. Otherwise, it is three-stated.
Bit 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Field D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W R/W
Addr 0x956
Figure 34-2. Port A Data Register (PADAT)
Table 34-3. PADAT Bit Descriptions
Bits Name Description
0Ð15 D n Contains the data on the corresponding signal.