MC68HC908LB8CPE Freescale Semiconductor, MC68HC908LB8CPE Datasheet - Page 166

• Manufacturer Part Number: MC68HC908LB8CPE
• Description: IC MCU 8K FLASH 8MHZ 20DIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LB8CPE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LVR, POR, PWM
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 7x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -

Resets and Interrupts
16.3 Interrupts
An interrupt temporarily changes the sequence of program execution to respond to a particular event. An
interrupt does not stop the operation of the instruction being executed, but begins when the current
instruction completes its operation.
16.3.1 Effects
An interrupt:
After every instruction, the CPU checks all pending interrupts if the I bit is not set. If more than one
interrupt is pending when an instruction is done, the highest priority interrupt is serviced first. In the
example shown in
pending interrupt is serviced before the LDA instruction is executed.
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Saves the CPU registers on the stack. At the end of the interrupt, the RTI instruction recovers the
CPU registers from the stack so that normal processing can resume.
Sets the interrupt mask (I bit) to prevent additional interrupts. Once an interrupt is latched, no other
interrupt can take precedence, regardless of its priority.
Loads the program counter with a user-defined vector address
STACKING
1. High byte of index register is not stacked.
ORDER
Figure
16-4, if an interrupt is pending upon exit from the interrupt service routine, the
5
4
3
2
1
PROGRAM COUNTER (HIGH BYTE)
PROGRAM COUNTER (LOW BYTE)
INDEX REGISTER (LOW BYTE)
Figure 16-3. Interrupt Stacking Order
CONDITION CODE REGISTER
MC68HC908LB8 Data Sheet, Rev. 1
ACCUMULATOR
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(1)
$00FF DEFAULT ADDRESS ON RESET
1
2
3
4
5
UNSTACKING
ORDER
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