SAB80C517-M16 SIEMENS [Siemens Semiconductor Group], SAB80C517-M16 Datasheet - Page 168

• Manufacturer Part Number: SAB80C517-M16
• Description: 8-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

9
The SAB 80C517 instruction set includes 111 instructions, 49 of which are single-byte, 45 two-byte
and 17 three-byte instructions. The instruction opcode format consists of a function mnemonic
followed by a ”destination, source” operand field. This field specifies the data type and addressing
method(s) to be used.
Like all other members of the 8051-family, the SAB 80C517 can be programmed with the same
instruction set common to the basic member, the SAB 8051.
Thus, the SAB 80C517 is 100% software compatible to the SAB 8051 and may be programmed
with 8051 assembler or high-level languages.
9.1
The SAB 80C517 uses five addressing modes:
Table 9-1 summarizes the memory spaces which may be accessed by each of the addressing
modes.
Register Addressing
Register addressing accesses the eight working registers (R0 - R7) of the selected register bank.
The least significant bit of the instruction opcode indicates which register is to be used. ACC, B,
DPTR and CY, the Boolean processor accumulator, can also be addressed as registers.
Direct Addressing
Direct addressing is the only method of accessing the special function registers. The lower
128 bytes of internal RAM are also directly addressable.
Immediate Addressing
Immediate addressing allows constants to be part of the instruction in program memory.
Semiconductor Group
– register
– direct
– immediate
– register indirect
– base register plus index-register indirect
Instruction Set
Addressing Modes
169
Instruction Set