MC908LJ24CFQE Freescale Semiconductor, MC908LJ24CFQE Datasheet - Page 411

• Manufacturer Part Number: MC908LJ24CFQE
• Description: IC MCU 24K FLASH 8MHZ SPI 80-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908LJ24CFQE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, IRSCI, SPI
• Peripherals: LCD, LVD, POR, PWM
• Number Of I /o: 48
• Program Memory Size: 24KB (24K x 8)
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-QFP
• Controller Family/series: HC08
• No. Of I/o's: 48
• Ram Memory Size: 768Byte
• Cpu Speed: 8MHz
• No. Of Timers: 2
• Embedded Interface Type: I2C, SCI, SPI
• Rohs Compliant: Yes
• Processor Series: HC08LJ
• Core: HC08
• Data Bus Width: 8 bit
• Data Ram Size: 768 B
• Interface Type: SCI, SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 48
• Number Of Timers: 4
• Operating Supply Voltage: 0 V to 5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: FSICEBASE, M68EML08LJLKE, ZK-HC08LX-A, M68CBL05CE
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 6 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

20.5.1 Keyboard Initialization
MC68HC908LJ24/LK24 — Rev. 2.1
Freescale Semiconductor
NOTE:
Setting a keyboard interrupt enable bit (KBIEx) forces the corresponding
keyboard interrupt pin to be an input, overriding the data direction
register. However, the data direction register bit must be a logic 0 for
software to read the pin.
When a keyboard interrupt pin is enabled, it takes time for the internal
pullup to reach a logic 1. Therefore a false interrupt can occur as soon
as the pin is enabled.
To prevent a false interrupt on keyboard initialization:
An interrupt signal on an edge-triggered pin can be acknowledged
immediately after enabling the pin. An interrupt signal on an edge- and
level-triggered interrupt pin must be acknowledged after a delay that
depends on the external load.
Another way to avoid a false interrupt:
1. Mask keyboard interrupts by setting the IMASKK bit in the
2. Enable the KBI pins by setting the appropriate KBIEx bits in the
3. Write to the ACKK bit in the keyboard status and control register
4. Clear the IMASKK bit.
1. Configure the keyboard pins as outputs by setting the appropriate
2. Write logic 1s to the appropriate data register bits.
3. Enable the KBI pins by setting the appropriate KBIEx bits in the
keyboard status and control register.
keyboard interrupt enable register.
to clear any false interrupts.
DDR bits in data direction register.
keyboard interrupt enable register.
Keyboard Interrupt Module (KBI)
Keyboard Interrupt Module (KBI)
Functional Description
Data Sheet
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