mc908jl16 Freescale Semiconductor, Inc, mc908jl16 Datasheet - Page 144

• Manufacturer Part Number: mc908jl16
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
When DDRBx is a logic 1, reading address $0001 reads the PTBx data latch. When DDRBx is a logic 0,
reading address $0001 reads the voltage level on the pin. The data latch can always be written,
regardless of the state of its data direction bit.
10.4 Port D
Port D is an 8-bit special function port that shares two of its pins with the serial communications interface
module (see
module (see
module (see
(see
and programmable pull-up. PTD2, PTD3, PTD6 and PTD7 each has LED sink capability.
144
Chapter 8 Multi-Master IIC Interface
DDRB Bit
1. X = don’t care.
2. Hi-Z = high impedance.
3. Writing affects data register, but does not affect the input.
Chapter 6 Timer Interface Module
Chapter 7 Serial Communications Interface
Chapter 9 Analog-to-Digital Converter
Avoid glitches on port B pins by writing to the port B data register before
changing data direction register B bits from 0 to 1.
port B I/O logic.
0
1
READ DDRB ($0005)
WRITE DDRB ($0005)
WRITE PTB ($0001)
READ PTB ($0001)
PTB Bit
X
X
(1)
I/O Pin Mode
RESET
Input, Hi-Z
Table 10-3. Port B Pin Functions
MC68HC908JL16 Data Sheet, Rev. 1.1
Figure 10-9. Port B I/O Circuit
Output
(MMIIC)). PTD6 and PTD7 each has high current sink (25mA)
(2)
Table 10-3
(TIM)), four of its pins with the analog-to-digital converter
NOTE
DDRBX
PTBX
Accesses to DDRB
(ADC)), and two of its pins with the MMIIC module
Read/Write
DDRB[7:0]
DDRB[7:0]
(SCI)), two of its pins with the timer 1 interface
summarizes the operation of the port B pins.
Figure 10-9
TO ANALOG-TO-DIGITAL CONVERTER
PTB[7:0]
Read
Pin
Accesses to PTB
shows the
PTB[7:0]
PTB[7:0]
Freescale Semiconductor
Write
PTBX
(3)