MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 116

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Input/Output Ports (PORTS)
12.4.3 Port B Input Pullup Enable Register
The port B input pullup enable register (PTBPUE) contains a software configurable pullup device for each
of the eight port B pins. Each bit is individually configurable and requires the corresponding data direction
register, DDRBx, be configured as input. Each pullup device is automatically and dynamically disabled
when its corresponding DDRBx bit is configured as output.
PTBPUE[7:0] — Port B Input Pullup Enable Bits
12.4.4 Port B Summary Table
The following table summarizes the operation of the port A pins when used as a general-purpose
input/output pins.
116
These read/write bits are software programmable to enable pullup devices on port B pins
1 = Corresponding port B pin configured to have internal pull if its DDRB bit is set to 0
0 = Pullup device is disconnected on the corresponding port B pin regardless of the state of its
DDRB bit.
Reset:
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect the input.
Read:
Write:
DDRB
Bit
0
1
PTBPUE7
Figure 12-8. Port B Input Pullup Enable Register (PTBPUE)
Bit 7
0
PTB
X
Bit
X
(1)
PTBPUE6
Input, Hi-Z
6
0
I/O Pin
Output
Mode
Table 12-2. Port B Pin Functions
MC68HC908QL4 Data Sheet, Rev. 7
PTBPUE5
(2)
5
0
Accesses to DDRB
PTBPUE4
DDRB7–DDRB0
DDRB7–DDRB0
4
0
Read/Write
PTBPUE3
3
0
PTBPUE2
2
0
Read
Pin
Pin
Accesses to PTB
PTBPUE2
PTB7–PTB0
1
0
PTB7–PTB0
Write
PTBPUE0
Freescale Semiconductor
Bit 0
0
(3)