MC908AZ32ACFU Freescale Semiconductor, MC908AZ32ACFU Datasheet - Page 226

• Manufacturer Part Number: MC908AZ32ACFU
• Description: IC MCU 32K FLASH 8.4MHZ 64-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908AZ32ACFU

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: CAN, SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 40
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 15x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Programmable Interrupt Timer (PIT)
POF — PIT Overflow Flag Bit
POIE — PIT Overflow Interrupt Enable Bit
PSTOP — PIT Stop Bit
PRST — PIT Reset Bit
PPS[2:0] — Prescaler Select Bits
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This read/write flag is set when the PIT counter resets to $0000 after reaching the modulo value
programmed in the PIT counter modulo registers. Clear POF by reading the PIT status and control
register when POF is set and then writing a logic 0 to POF. If another PIT overflow occurs before the
clearing sequence is complete, then writing logic 0 to POF has no effect. Therefore, a POF interrupt
request cannot be lost due to inadvertent clearing of POF. Reset clears the POF bit. Writing a logic 1
to POF has no effect.
This read/write bit enables PIT overflow interrupts when the POF bit becomes set. Reset clears the
POIE bit.
This read/write bit stops the PIT counter. Counting resumes when PSTOP is cleared. Reset sets the
PSTOP bit, stopping the PIT counter until software clears the PSTOP bit.
Setting this write-only bit resets the PIT counter and the PIT prescaler. Setting PRST has no effect on
any other registers. Counting resumes from $0000. PRST is cleared automatically after the PIT
counter is reset and always reads as logic zero. Reset clears the PRST bit.
These read/write bits select one of the seven prescaler outputs as the input to the PIT counter as
20-2
1 = PIT counter has reached modulo value
0 = PIT counter has not reached modulo value
1 = PIT overflow interrupts enabled
0 = PIT overflow interrupts disabled
1 = PIT counter stopped
0 = PIT counter active
1 = Prescaler and PIT counter cleared
0 = No effect
shows. Reset clears the PPS[2:0] bits.
Do not set the PSTOP bit before entering wait mode if the PIT is required
to exit wait mode.
Setting the PSTOP and PRST bits simultaneously stops the PIT counter at
a value of $0000.
PPS[2:0]
000
001
010
011
100
101
110
111
Table 20-2. Prescaler Selection
MC68HC908AZ32A Data Sheet, Rev. 2
NOTE
NOTE
Internal Bus Clock ÷ 16
Internal Bus Clock ÷ 32
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 2
Internal Bus Clock ÷ 4
Internal Bus Clock ÷ 8
Internal Bus Clock ÷1
PIT Clock Source
Freescale Semiconductor
Table