MC68HC908JK3EMP MOTOROLA [Motorola, Inc], MC68HC908JK3EMP Datasheet - Page 174
MC68HC908JK3EMP
Manufacturer Part Number
MC68HC908JK3EMP
Description
Microcontrollers
Manufacturer
MOTOROLA [Motorola, Inc]
Datasheet
1.MC68HC908JK3EMP.pdf
(226 pages)
- Current page: 174 of 226
- Download datasheet (2Mb)
Keyboard Interrupt Module (KBI)
14.4.1 Keyboard Initialization
Technical Data
174
NOTE:
If the MODEK bit is clear, the keyboard interrupt pin is falling-edge-
sensitive only. With MODEK clear, a vector fetch or software clear
immediately clears the keyboard interrupt request.
Reset clears the keyboard interrupt request and the MODEK bit, clearing
the interrupt request even if a keyboard interrupt pin stays at logic 0.
The keyboard flag bit (KEYF) in the keyboard status and control register
can be used to see if a pending interrupt exists. The KEYF bit is not
affected by the keyboard interrupt mask bit (IMASKK) which makes it
useful in applications where polling is preferred.
To determine the logic level on a keyboard interrupt pin, disable the pull-
up device, use the data direction register to configure the pin as an input
and then read the data register.
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
pull-up 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
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.
keyboard status and control register.
keyboard interrupt enable register.
to clear any false interrupts.
Keyboard Interrupt Module (KBI)
MC68H(R)C908JL3E/JK3E/JK1E
MOTOROLA
—
Rev. 2.0
Related parts for MC68HC908JK3EMP
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Motorola, Inc [VOLTAGE REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
6367254 MOTOROLA SC (XSTRS/R F)
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
MC1494LMotorola, Inc [MONOLITHIC FOUR-QUADRANT MULTIPLIER]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC1466LMotorola, Inc [PRECISION WIDE RANGE VOLTAGE AND CURRENT REGULATOR]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
MC145532DWMotorola, Inc [ADPCM Transcoder]
Manufacturer:
Motorola
Datasheet:
Part Number:
Description:
Silicon Controlled Rectifiers
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF Power Field Effect Transistors N-Channel Enhancement-Mode Lateral MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTORS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
LATERAL N-CHANNEL BROADBAND RF POWER MOSFETs
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF POWER FIELD EFFECT TRANSISTOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
RF LOW POWER TRANSISTOR NPN SILICON
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
PLASTIC SURFACE MOUNT ZENER DIODES 1.5 WATTS 3.3-68 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
OVERVOLTAGE TRANSIENT SUPPRESSOR
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET 15 AMPERES 60 VOLTS
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet:
Part Number:
Description:
TMOS POWER FET LOGIC LEVEL 19 AMPERES 30 VOLTS RDS(on) = 0.099 OHM
Manufacturer:
MOTOROLA [Motorola, Inc]
Datasheet: