MC908SR12MFAER Freescale Semiconductor, MC908SR12MFAER Datasheet - Page 338

• Manufacturer Part Number: MC908SR12MFAER
• Description: IC MCU 12K FLASH 4/8MHZ 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908SR12MFAER

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SCI
• Peripherals: LVD, POR, PWM, Temp Sensor
• Number Of I /o: 31
• Program Memory Size: 12KB (12K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 48-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: MC908SR12MFAER; MC908SR12MFAERTR

External Interrupt (IRQ)
19.5 IRQ1 and IRQ2 Pins
Data Sheet
338
IRQ2
V
DD
DECODER
INTERNAL
PULLUP
DEVICE
VECTOR
FETCH
RESET
ACK2
PTBPUE6
A logic 0 on the IRQ pin can latch an interrupt request into the IRQ latch.
A vector fetch, software clear, or reset clears the IRQ latch.
If the MODE bit is set, the IRQ pin is both falling-edge-sensitive and low-
level-sensitive. With MODE set, both of the following actions must occur
to clear IRQ:
•
MODE2
V
Vector fetch or software clear — A vector fetch generates an
interrupt acknowledge signal to clear the latch. Software may
generate the interrupt acknowledge signal by writing a logic 1 to
the ACK bit in the interrupt status and control register (INTSCR).
The ACK bit is useful in applications that poll the IRQ pin and
require software to clear the IRQ latch. Writing to the ACK bit prior
to leaving an interrupt service routine can also prevent spurious
interrupts due to noise. Setting ACK does not affect subsequent
transitions on the IRQ pin. A falling edge that occurs after writing
to the ACK bit another interrupt request. If the IRQ mask bit,
IMASK, is clear, the CPU loads the program counter with the
vector address at location defined in
Addresses.
Figure 19-3. IRQ2 Block Diagram
DD
D
CK
IRQ2
CLR
FF
External Interrupt (IRQ)
Q
IMASK2
MC68HC908SR12•MC68HC08SR12 — Rev. 5.0
SYNCHRO-
NIZER
Table 2-1 . Vector
Freescale Semiconductor
IRQ2F
IRQ2
INTERRUPT
REQUEST