MC68HC908GR8CD Freescale Semiconductor, MC68HC908GR8CD Datasheet - Page 101

• Manufacturer Part Number: MC68HC908GR8CD
• Description: 8-bit Microcontrollers - MCU 8 Bit 8MHz
• Manufacturer: Freescale Semiconductor

Specifications of MC68HC908GR8CD

• Product Category: 8-bit Microcontrollers - MCU
• Rohs: yes
• Core: HC08
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 8 MHz
• Program Memory Size: 64 KB
• Data Ram Size: 384 B
• Operating Supply Voltage: 3 V to 5 V
• Package / Case: SOIC-28
• Mounting Style: SMD/SMT
• Data Rom Size: 64 KB
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Number Of Programmable I/os: 21
• Program Memory Type: Flash

Z — Zero Flag
C — Carry/Borrow Flag
10.3 Arithmetic/Logic Unit (ALU)
The ALU performs the arithmetic and logic operations defined by the instruction set.
Refer to the CPU08 Reference Manual (document order number CPU08RM/AD) for a description of the
instructions and addressing modes and more detail about the architecture of the CPU.
10.4 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power-consumption standby modes.
10.4.1 Wait Mode
The WAIT instruction:
10.4.2 Stop Mode
The STOP instruction:
After exiting stop mode, the CPU clock begins running after the oscillator stabilization delay.
10.5 CPU During Break Interrupts
If a break module is present on the MCU, the CPU starts a break interrupt by:
The break interrupt begins after completion of the CPU instruction in progress. If the break address
register match occurs on the last cycle of a CPU instruction, the break interrupt begins immediately.
Freescale Semiconductor
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.
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1 = Zero result
0 = Non-zero result
1 = Carry out of bit 7
0 = No carry out of bit 7
Clears the interrupt mask (I bit) in the condition code register, enabling interrupts. After exit from
wait mode by interrupt, the I bit remains clear. After exit by reset, the I bit is set.
Disables the CPU clock
Clears the interrupt mask (I bit) in the condition code register, enabling external interrupts. After
exit from stop mode by external interrupt, the I bit remains clear. After exit by reset, the I bit is set.
Disables the CPU clock
Loading the instruction register with the SWI instruction
Loading the program counter with $FFFC:$FFFD or with $FEFC:$FEFD in monitor mode
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
Arithmetic/Logic Unit (ALU)
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