sc9s08mz16 Freescale Semiconductor, Inc, sc9s08mz16 Datasheet - Page 105

• Manufacturer Part Number: sc9s08mz16
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

of an operand for a test and then use relative addressing mode to specify the branch destination address
when the tested condition is true. For BRCLR, BRSET, CBEQ, and DBNZ, the addressing mode listed in
the instruction set tables is the addressing mode needed to access the operand to be tested, and relative
addressing mode is implied for the branch destination.
7.3.1
In this addressing mode, operands needed to complete the instruction (if any) are located within CPU
registers so the CPU does not need to access memory to get any operands.
7.3.2
Relative addressing mode is used to specify the destination location for branch instructions. A signed 8-bit
offset value is located in the memory location immediately following the opcode. During execution, if the
branch condition is true, the signed offset is sign-extended to a 16-bit value and is added to the current
contents of the program counter, which causes program execution to continue at the branch destination
address.
7.3.3
In immediate addressing mode, the operand needed to complete the instruction is included in the object
code immediately following the instruction opcode in memory. In the case of a 16-bit immediate operand,
the high-order byte is located in the next memory location after the opcode, and the low-order byte is
located in the next memory location after that.
7.3.4
In direct addressing mode, the instruction includes the low-order eight bits of an address in the direct page
(0x0000–0x00FF). During execution a 16-bit address is formed by concatenating an implied 0x00 for the
high-order half of the address and the direct address from the instruction to get the 16-bit address where
the desired operand is located. This is faster and more memory efficient than specifying a complete 16-bit
address for the operand.
7.3.5
In extended addressing mode, the full 16-bit address of the operand is located in the next two bytes of
program memory after the opcode (high byte first).
7.3.6
Indexed addressing mode has seven variations including five that use the 16-bit H:X index register pair
and two that use the stack pointer as the base reference.
Freescale Semiconductor
Inherent Addressing Mode (INH)
Relative Addressing Mode (REL)
Immediate Addressing Mode (IMM)
Direct Addressing Mode (DIR)
Extended Addressing Mode (EXT)
Indexed Addressing Mode
SC9S08MZ16 MCU Data Sheet, Rev. 1
Chapter 7 Central Processor Unit (S08CPUV2)
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