We can carry out the Locked Microprocessor SN8P2267 Embedded Firmware Copying, please view the SN802267 features for your reference:
A summary of the instructions in the extended instruction set is provided in Table 24-3. Detailed descriptions are provided in Section 24.2.2 “Extended Instruction Set”. The opcode field descriptions in Table 24-1 (page 268) apply to both the standard and extended SN8P2267 instruction sets. The instruction set extension and the Indexed Literal Offset Addressing mode were designed for optimizing applications written in C; the user may likely never use these instructions directly in assembler.
The syntax for these commands is provided as a reference for users who may be reviewing code that has been generated by a compiler. Most of the extended instructions use indexed arguments, using one of the File Select Registers and some offset to specify a source or destination register.
When an argument for an instruction serves as part of indexed addressing, it is enclosed in square brackets (“[ ]”). This is done to indicate that the argument is used as an index or offset. MPASM™ Assembler will flag an error if it determines that an index or offset value is not bracketed when copy binary from MCU.
When the extended instruction set is enabled, brackets are also used to indicate index arguments in byte-oriented and bit-oriented instructions. This is in addition to other changes in their syntax. For more details, see
In the past, square brackets have been used to denote optional arguments in the SN8P2267 and earlier instruction sets. In this text and going forward, optional arguments are denoted by braces (“{ }”). Enabling the PIC18 instruction set extension may cause legacy applications to behave erratically or fail entirely before the Microprocessor’s firmware has been copied.
In addition to eight new commands in the extended set, enabling the extended instruction set also enables Indexed Literal Offset Addressing mode (Section 5.5.1 “Indexed Addressing with Literal Offset”). This has a significant impact on the way that many commands of the standard PIC18 instruction set are interpreted. When the extended set is disabled, addresses embedded in opcodes are treated as literal memory locations:
either as a location in the Access Bank (‘a’ = 0), or in a GPR bank designated by the BSR (‘a’ = 1). When the extended instruction set is enabled and ‘a’ = 0, however, a file register argument of 5Fh or less is interpreted as an offset from the pointer value in FSR2 and not as a literal address.
For practical purposes, this means that all instructions that use the Access RAM bit as an argument – that is, all byte-oriented and bit-oriented instructions, or almost half of the core PIC18 instructions – may behave differently when the extended instruction set is enabled.
