Communication Processor Module
MOTOROLA MPC823e REFERENCE MANUAL 16-485
PORTS
COMMUNICATION
16
PROCESSOR MODULE
16.14.6 The Port B Registers
Port B has four memory-mapped, read-write control registers.
16.14.6.1 PORT B OPEN-DRAIN REGISTER. The 16-bit port B open drain register
(PBODR) indicates when the port pins are configured in a a normal or wired-OR
configuration. Bits 0 and 15 of this register are reserved.
Bits 0–15—Reserved
These bits are reserved and must be set to 0.
OD16–OD31—Open-Drain Pins 16-31
0 = The I/O pin is actively driven as an output.
1 = The I/O pin is an open-drain driver. As an output, the pin is actively driven low.
Otherwise, it is three-stated.
PB17 PORT B17 L1ST3 LCD_C —
PB16 PORT B16 L1ST4 L1RQA —
PBODR
BIT 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
FIELD
RESERVED
RESET
0
R/W
R/W
ADDR
(IMMR & 0xFFFF0000) + 0x
AC0
BIT 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
FIELD
OD16 OD17 OD18 OD19 OD20 OD21 OD22 OD23 OD24 OD25 OD26 OD27 OD28 OD29 OD30 OD31
RESET
0000000000000000
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
(IMMR & 0xFFFF0000) + 0x
AC2
Note: SMTXD1 cannot be set as an open-drain driver, regardless of how this register
is set.
Table 16-42. Port B Pin Assignment
SIGNAL PIN FUNCTION
PBPAR = 0 PBPAR = 1 INPUT TO ON-CHIP
PERIPHERALS
PBDIR = 0 PBDIR = 1
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