MC68HC908JK8CP Freescale Semiconductor, MC68HC908JK8CP Datasheet - Page 156

• Manufacturer Part Number: MC68HC908JK8CP
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC908JK8CP

• Cpu Family: HC08
• Device Core Size: 8b
• Frequency (max): 8MHz
• Interface Type: SCI
• Program Memory Type: Flash
• Program Memory Size: 8KB
• Total Internal Ram Size: 256Byte
• # I/os (max): 15
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 13-chx8-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 20
• Package Type: PDIP
• Lead Free Status / Rohs Status: Not Compliant

Input/Output (I/O) Ports
11.3 Port B
Port B is an 8-bit special function port that shares all of its port pins with the analog-to-digital converter
(ADC) module, see
11.3.1 Port B Data Register (PTB)
The port B data register contains a data latch for each of the eight port B pins.
PTB[7:0] — Port B Data Bits
ADC7–ADC0 — ADC channels 7 to 0
11.3.2 Data Direction Register B (DDRB)
Data direction register B determines whether each port B pin is an input or an output. Writing a logic 1 to
a DDRB bit enables the output buffer for the corresponding port B pin; a logic 0 disables the output buffer.
DDRB[7:0] — Data Direction Register B Bits
156
These read/write bits are software programmable. Data direction of each port B pin is under the control
of the corresponding bit in data direction register B. Reset has no effect on port B data.
ADC7–ADC0 are pins used for the input channels to the analog-to-digital converter module. The
channel select bits, ADCH[4:0], in the ADC status and control register define which port pin will be used
as an ADC input and overrides any control from the port I/O logic. See
Converter
These read/write bits control port B data direction. Reset clears DDRB[7:0], configuring all port B pins
as inputs.
1 = Corresponding port B pin configured as output
0 = Corresponding port B pin configured as input
Alternative Functions:
Address:
(ADC).
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.
Reset:
Read:
Write:
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Address:
Chapter 10
Reset:
Read:
Write:
DDRB7
$0005
Bit 7
0
Figure 11-8. Data Direction Register B (DDRB)
$0001
PTB7
ADC7
Bit 7
Figure 11-7. Port B Data Register (PTB)
DDRB6
6
0
PTB6
ADC6
6
DDRB5
5
0
ADC5
PTB5
5
NOTE
DDRB4
4
0
Unaffected by reset
ADC4
PTB4
4
DDRB3
3
0
ADC3
PTB3
3
Figure 11-9
DDRB2
2
0
ADC2
PTB2
Chapter 10 Analog-to-Digital
2
DDRB1
shows the
1
0
ADC2
PTB1
1
Freescale Semiconductor
DDRB0
Bit 0
0
PTB0
ADC0
Bit 0