Extract Code of Encrypted Microcomputer PIC18F4553 in the format of binary or heximal, in order to locate the security fuse bits on the MCU which will lock the memory content;
The Status register, shown in Register 5-2, contains the arithmetic status of the ALU. As with any other SFR, it can be the operand for any instruction. If the Status register is the destination for an instruction that affects the Z, DC, C, OV or N bits, the results of the instruction are not written; instead, the Status register is updated according to the instruction performed.
Therefore, the result of an instruction with the Status register as its destination may be different than intended. As an example, CLRF STATUS will set the Z bit and leave the remaining status bits unchanged (‘000u u1uu’). It is recommended that only BCF, BSF, SWAPF, MOVFF and MOVWF instructions are used to alter the Status register, because these instructions do not affect the Z, C, DC, OV or N bits in the Status register.
For other instructions that do not affect Status bits. While the program memory can be addressed in only one way – through the program counter – information in the data memory space can be addressed in several ways when clone IC data. For most instructions, the addressing mode is fixed. Other instructions may use up to three modes, depending on which operands are used and whether or not the extended instruction set is enabled before extract ts87c54x2 firmware from Microcontroller.
The addressing modes are:
Inherent
Literal
Direct•
Indirect An additional addressing mode, Indexed Literal Offset, is available when the extended instruction set is enabled (XINST configuration bit = 1). Its operation is discussed in greater detail in Section 5.5.1 “Indexed Addressing with Literal Offset”. Many PIC18 control instructions do not need any argument at all; they either perform an operation that globally affects the device or they operate implicitly on one register. This addressing mode is known as Inherent Addressing. Examples includeSLEEP, RESET andDAW after the extract ts87c58x2 hex.
Other instructions work in a similar way but require an additional explicit argument in the opcode. This is known as Literal Addressing mode because theyrequire some literal value as an argument. Examples include ADDLW and MOVLW, which respectively, add or move a literal value to the W register. Other examples include CALL and GOTO, which include a 20-bit program memory address.
Direct addressing specifies all or part of the source and/or destination address of the operation within the opcode itself. The options are specified by the arguments accompanying the instruction. In the core PIC18 instruction set, bit-oriented and byte oriented instructions use some version of direct addressing by default. All of these instructions include some 8-bit literal address as their Least Significant Byte.
This address specifies either a register address in one of the banks of data RAM (Section 5.3.3 “General Purpose Register File”) or a location in the Access Bank (Section 5.3.2 “Access Bank”) as the data source for the instruction.
