MC68HC908QY2 MOTOROLA [Motorola, Inc], MC68HC908QY2 Datasheet - Page 185

• Manufacturer Part Number: MC68HC908QY2
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

14.4.4 Auto Wake-up Interrupt Request
MOTOROLA
(CGMXCLK)
MC68HC908QY4•MC68HC908QT4•MC68HC908QY2•MC68HC908QT2•MC68HC908QY1•MC68HC908QT1
BUSCLKX4
RESET
Figure 14-5. Auto Wake-up Interrupt Request Generation Logic
CLK
CLRLOGIC
COPRS (FROM CONFIG1)
EN
RST
INT RC OSC
CLEAR
The function of the auto wake-up logic is to generate periodic wake-up
requests to bring the microcontroller unit (MCU) out of stop mode. The
wake-up requests are treated as regular keyboard interrupt requests,
with the difference that instead of a pin, the interrupt signal is generated
by an internal logic.
Entering stop mode will enable the auto wake-up generation logic. An
internal RC oscillator (exclusive for the auto wake-up feature) drives the
wake-up request generator. Once the overflow count is reached in the
generator counter, a wake-up request, AWUIREQ, is latched and sent to
the KBI logic (see
Wake-up interrupt requests will only be serviced if the associated
interrupt enable bit, AWUIE, in KBIER is set.
32KHz
RESET
AWUIE
Keyboard Interrupt Module (KBI)
SHORT
CLK
AUTOWUGEN
ISTOP
OVERFLOW
RST
1 = DIV 2
0 = DIV 2
Figure
9
14
14-2).
RESET
ACKK
V
DD
D
E
Keyboard Interrupt Module (KBI)
R
Q
Functional Description
TO KBI INTERRUPT LOGIC
(SEE
TO PTA READ, BIT 6
Figure
14-2)
AWUIREQ
AWUL
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