MC68HC912B32CFU8 Freescale Semiconductor, MC68HC912B32CFU8 Datasheet - Page 65

• Manufacturer Part Number: MC68HC912B32CFU8
• Description: IC MCU 32K FLASH 8MHZ 80-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC12r

Specifications of MC68HC912B32CFU8

• Core Processor: CPU12
• Core Size: 16-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 63
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 768 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 80-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Opcodes and Operands
3.7 Opcodes and Operands
The CPU12 uses 8-bit opcodes. Each opcode identifies a particular instruction and associated addressing
mode to the CPU. Several opcodes are required to provide each instruction with a range of addressing
capabilities.
Only 256 opcodes would be available if the range of values were restricted to the number that can be
represented by 8-bit binary numbers. To expand the number of opcodes, a second page is added to the
opcode map. Opcodes on the second page are preceded by an additional byte with the value $18.
To provide additional addressing flexibility, opcodes can also be followed by a postbyte or extension
bytes. Postbytes implement certain forms of indexed addressing, transfers, exchanges, and loop
primitives. Extension bytes contain additional program information such as addresses, offsets, and
immediate data.
M68HC12B Family Data Sheet, Rev. 9.1
Freescale Semiconductor
65