mc68hc908rf2 Freescale Semiconductor, Inc, mc68hc908rf2 Datasheet - Page 112

• Manufacturer Part Number: mc68hc908rf2
• Description: M68hc08 Microcontrollers Microcontroller / Transmitter
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
Data Sheet
112
When bit DDRBx is a 1, reading address $0001 reads the PTBx data latch. When
bit DDRBx is a 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.
Table 9-2
X = Don’t care
Hi-Z = High impedance
1. Writing affects data register, but does not affect input.
DDRB
Bit
0
1
Freescale Semiconductor, Inc.
For More Information On This Product,
READ DDRB ($0005)
WRITE DDRB ($0005)
WRITE PTB ($0001)
READ PTB ($0001)
summarizes the operation of the port B pins.
PTB
Bit
X
X
Go to: www.freescale.com
Input, Hi-Z
Input/Output (I/O) Ports
I/O Pin
Output
Mode
RESET
Table 9-2. Port B Pin Functions
Figure 9-7. Port B I/O Circuit
Accesses to DDRB
DDRBx
Read/Write
DDRB[3:0]
DDRB[3:0]
PTBx
DDRB[7]
DDRB[7]
PTB[3:0]
MC68HC908RF2 — Rev. 4.0
Read
Pin
Accesses to PTB
PTB[3:0]
PTB[3:0]
MOTOROLA
Write
PTBx
(1)