
Digital Core Design
OVERVIEW
DOCUMENT STRUCTURE.
Document contains brief description of DP805X instructions. This manual is intended for design engineers who are planning to use the DP805X HDL core in conjunction with software assembler, compiler and debugger tools.
INSTRUCTIONS SET BRIEF
INSTRUCTION SET NOTES
The DP805X has five different addressing modes: immediate, direct, register, indirect and relative. In the immediate addressing mode the data is contained in the opcode. By direct addressing an eight bit address is a part of the opcode, by register addressing, a register is selected in the opcode for the operation. In the indirect addressing mode, a register is selected in the opcode to point to the address used by the operation. The relative addressing mode is used for jump instructions.
The following tables give a survey about the instruction set cycles of the DP805X microcontroller core. One cycle is equal to one clock period.
Table 1 and Table 2 contain notes for mnemonics used in Instruction set tables. Tables 3 - 7 show instruction hexadecimal codes, number of bytes and machine cycles that each instruction takes to execute.