MCHC908GR8AVFAE Freescale Semiconductor, MCHC908GR8AVFAE Datasheet - Page 101

• Manufacturer Part Number: MCHC908GR8AVFAE
• Description: IC MCU 8K FLASH 8MHZ 32-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MCHC908GR8AVFAE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 21
• Program Memory Size: 7.5KB (7.5K x 8)
• Program Memory Type: FLASH
• Ram Size: 384 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

If the MODEK bit is set, the keyboard interrupt pins are both falling edge- and low-level sensitive, and both
of the following actions must occur to clear a keyboard interrupt request:
Freescale Semiconductor
TO PULLUP ENABLE
TO PULLUP ENABLE
$001A
$001B
Addr.
•
•
Vector fetch or software clear — A vector fetch generates an interrupt acknowledge signal to clear
the interrupt request. Software may generate the interrupt acknowledge signal by writing a 1 to the
ACKK bit in the keyboard status and control register (INTKBSCR). The ACKK bit is useful in
applications that poll the keyboard interrupt pins and require software to clear the keyboard
interrupt request. Writing to the ACKK bit prior to leaving an interrupt service routine can also
prevent spurious interrupts due to noise. Setting ACKK does not affect subsequent transitions on
the keyboard interrupt pins. A falling edge that occurs after writing to the ACKK bit latches another
interrupt request. If the keyboard interrupt mask bit, IMASKK, is clear, the CPU loads the program
counter with the vector address at locations $FFE0 and $FFE1.
Return of all enabled keyboard interrupt pins to a high level — As long as any enabled keyboard
interrupt pin is low, the keyboard interrupt remains set.
KBD0
KBD3
Keyboard Interrupt Enable
Register Name
and Control Register
VECTOR FETCH
Keyboard Status
KBIE0
KBIE3
INTERNAL BUS
See page 103.
See page 104.
DECODER
(INTKBSCR)
(INTKBIER)
Register
.
.
.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Reset:
Reset:
Figure 9-2. Keyboard Module Block Diagram
Read:
Read:
Write:
Write:
RESET
ACKK
Figure 9-3. I/O Register Summary
Bit 7
0
0
0
MODEK
= Unimplemented
V
6
0
0
0
DD
D
CK
CLR
5
0
0
0
Q
4
0
0
0
IMASKK
KBIE3
KEYF
SYNCHRONIZER
3
0
0
ACKK
KBIE2
2
0
0
0
KEYF
Functional Description
IMASKK
KBIE1
1
0
0
KEYBOARD
INTERRUPT
REQUEST
MODEK
KBIE0
Bit 0
0
0
101