MC68HC908JK3EMP MOTOROLA [Motorola, Inc], MC68HC908JK3EMP Datasheet - Page 63

• Manufacturer Part Number: MC68HC908JK3EMP
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

MC68H(R)C908JL3E/JK3E/JK1E
MOTOROLA
NOTE:
To maintain M6805 Family compatibility, the upper byte of the index
register (H) is not stacked automatically. If the interrupt service routine
modifies H, then the user must stack and unstack H using the PSHH and
PULH instructions.
N — Negative flag
Z — Zero flag
C — Carry/Borrow Flag
After the I bit is cleared, the highest-priority interrupt request is
serviced first.
A return-from-interrupt (RTI) instruction pulls the CPU registers from
the stack and restores the interrupt mask from the stack. After any
reset, the interrupt mask is set and can be cleared only by the clear
interrupt mask software instruction (CLI).
The CPU sets the negative flag when an arithmetic operation, logic
operation, or data manipulation produces a negative result, setting
bit 7 of the result.
The CPU sets the zero flag when an arithmetic operation, logic
operation, or data manipulation produces a result of $00.
The CPU sets the carry/borrow flag when an addition operation
produces a carry out of bit 7 of the accumulator or when a subtraction
operation requires a borrow. Some instructions — such as bit test and
branch, shift, and rotate — also clear or set the carry/borrow flag.
—
1 = Negative result
0 = Non-negative result
1 = Zero result
0 = Non-zero result
1 = Carry out of bit 7
0 = No carry out of bit 7
Rev. 2.0
Central Processor Unit (CPU)
Central Processor Unit (CPU)
CPU Registers
Technical Data
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