MC908GR16VFAE Freescale Semiconductor, MC908GR16VFAE Datasheet - Page 102

• Manufacturer Part Number: MC908GR16VFAE
• Description: IC MCU 16K FLASH 8MHZ 48-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908GR16VFAE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: LIN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 37
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 48-LQFP
• Controller Family/series: HC08
• No. Of I/o's: 37
• Ram Memory Size: 1KB
• Cpu Speed: 8MHz
• No. Of Timers: 2
• Embedded Interface Type: SCI, SPI
• Rohs Compliant: Yes
• Processor Series: HC08GR
• Core: HC08
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SCI, SPI
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 4
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Development Tools By Supplier: FSICEBASE, DEMO908GZ60E, M68CBL05CE, M68EML08GPGTE
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

External Interrupt (IRQ)
8.4 IRQ Pin
A falling edge on the IRQ pin can latch an interrupt request into the IRQ latch. A vector fetch, software
clear, or reset clears the IRQ latch.
The vector fetch or software clear and the return of the IRQ pin to logic 1 may occur in any order. The
interrupt request remains pending as long as the IRQ pin is at 0. A reset will clear the latch and the MODE
control bit, thereby clearing the interrupt even if the pin stays low.
If the MODE bit is clear, the IRQ pin is falling-edge-sensitive only. With MODE clear, a vector fetch or
software clear immediately clears the IRQ latch.
The IRQF bit in the INTSCR register can be used to check for pending interrupts. The IRQF bit is not
affected by the IMASK bit, which makes it useful in applications where polling is preferred.
Use the BIH or BIL instruction to read the logic level on the IRQ pin.
8.5 IRQ Module During Break Interrupts
The BCFE bit in the SIM break flag control register (SBFCR) enables software to clear the latch during
the break state. See
To allow software to clear the IRQ latch during a break interrupt, write a 1 to the BCFE bit. If a latch is
cleared during the break state, it remains cleared when the MCU exits the break state.
To protect CPU interrupt flags during the break state, write a 0 to the BCFE bit. With BCFE at 0 (its default
state), writing to the ACK bit in the IRQ status and control register during the break state has no effect on
the IRQ interrupt flags.
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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:
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 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 locations $FFFA and $FFFB.
Return of the IRQ pin to 1 — As long as the IRQ pin is at logic 0, IRQ remains active.
When using the level-sensitive interrupt trigger, avoid false interrupts by
masking interrupt requests in the interrupt routine.
Chapter 19 Development
MC68HC908GR16 Data Sheet, Rev. 5.0
Support.
NOTE
Freescale Semiconductor