MC68HC908LB8CPE Freescale Semiconductor, MC68HC908LB8CPE Datasheet - Page 68

• 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: -

Central Processor Unit (CPU)
7.3.1 Accumulator
The accumulator is a general-purpose 8-bit register. The CPU uses the accumulator to hold operands and
the results of arithmetic/logic operations.
7.3.2 Index Register
The 16-bit index register allows indexed addressing of a 64-Kbyte memory space. H is the upper byte of
the index register, and X is the lower byte. H:X is the concatenated 16-bit index register.
In the indexed addressing modes, the CPU uses the contents of the index register to determine the
conditional address of the operand.
The index register can serve also as a temporary data storage location.
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Reset:
Reset:
Read:
Read:
Write:
Write:
15
15
15
X = Indeterminate
Bit
15
0
Bit 7
14
0
H
13
0
6
Figure 7-3. Index Register (H:X)
12
0
MC68HC908LB8 Data Sheet, Rev. 1
Figure 7-2. Accumulator (A)
Figure 7-1. CPU Registers
7
7
V 1 1 H I N Z C
11
0
5
10
0
X
9
0
Unaffected by reset
4
8
0
0
0
0
0
0
ACCUMULATOR (A)
INDEX REGISTER (H:X)
STACK POINTER (SP)
PROGRAM COUNTER (PC)
CONDITION CODE REGISTER (CCR)
CARRY/BORROW FLAG
ZERO FLAG
NEGATIVE FLAG
INTERRUPT MASK
HALF-CARRY FLAG
TWO’S COMPLEMENT OVERFLOW FLAG
X
7
3
6
X
X
5
2
4
X
X
3
1
2
X
Freescale Semiconductor
X
1
Bit 0
Bit
X
0