mc68hc908mr8 Freescale Semiconductor, Inc, mc68hc908mr8 Datasheet - Page 286

• Manufacturer Part Number: mc68hc908mr8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
14.5 Port C
Technical Data
286
When bit DDRBx is a logic 1, reading address $0001 reads the PTBx
data latch. When bit 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.
the operation of the port B pins.
Port C is a 2-bit special-purpose I/O port sharing its pins with the pulse
width modulator for motor control module (PMC) FAULT input pins.
These two pins mirror the state of FAULT1 and FAULT4 pins. Level
changes on these input pins will be interpreted as fault conditions.
The port C data register contains a data latch for each of the two port
pins.
DDRB
1. X = don’t care
2. Hi-Z = high impedance
3. Writing affects data register, but does not affect input.
Bit
0
1
READ DDRB ($0005)
WRITE DDRB ($0005)
WRITE PTB ($0001)
READ PTB ($0001)
PTB
X
Bit
X
Input/Output (I/O) Ports
(1)
Table 14-2. Port B Pin Functions
Figure 14-7. Port B I/O Circuit
RESET
I/O Pin Mode
Input, Hi-Z
Output
(2)
DDRBx
PTBx
Read/Write
DDRB[6:0]
DDRB[6:0]
Accesses
to DDRB
Table 14-2
MC68HC908MR8 — Rev 4.1
Freescale Semiconductor
PTB[6:0]
Read
Accesses to PTB
Pin
summarizes
PTB[6:0]
PTB[6:0]
Write
PTBx
(3)