MC9S08QG8CPBE Freescale, MC9S08QG8CPBE Datasheet - Page 181

• Manufacturer Part Number: MC9S08QG8CPBE
• Manufacturer: Freescale

Specifications of MC9S08QG8CPBE

• Cpu Family: HCS08
• Device Core Size: 8b
• Frequency (max): 20MHz
• Interface Type: I2C/SCI/SPI
• Total Internal Ram Size: 512Byte
• # I/os (max): 12
• Number Of Timers - General Purpose: 1
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.6V
• Operating Supply Voltage (min): 1.8V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: CISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Through Hole
• Pin Count: 16
• Package Type: PDIP
• Program Memory Type: Flash
• Program Memory Size: 8KB
• Lead Free Status / RoHS Status: Compliant

KBISC provided all enabled keyboard inputs are at their deasserted levels. KBF will remain set if any
enabled KBI pin is asserted while attempting to clear by writing a 1 to KBACK.
12.4.3
The KBI pins can be configured to use an internal pullup/pulldown resistor using the associated I/O port
pullup enable register. If an internal resistor is enabled, the KBIES register is used to select whether the
resistor is a pullup (KBEDGn = 0) or a pulldown (KBEDGn = 1).
12.4.4
When a keyboard interrupt pin is first enabled it is possible to get a false keyboard interrupt flag. To
prevent a false interrupt request during keyboard initialization, the user should do the following:
Freescale Semiconductor
1. Mask keyboard interrupts by clearing KBIE in KBISC.
2. Enable the KBI polarity by setting the appropriate KBEDGn bits in KBIES.
3. If using internal pullup/pulldown device, configure the associated pullup enable bits in PTxPE.
4. Enable the KBI pins by setting the appropriate KBIPEn bits in KBIPE.
5. Write to KBACK in KBISC to clear any false interrupts.
6. Set KBIE in KBISC to enable interrupts.
KBI Pullup/Pulldown Resistors
KBI Initialization
MC9S08QG8 and MC9S08QG4 Data Sheet, Rev. 5
Keyboard Interrupts (S08KBIV2)
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