SAB80C517_05 Datasheet, PDF (171/323 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller

Instruction Set
General-Purpose Transfers
– MOV performs a bit or byte transfer from the source operand to the destination operand.
– PUSH increments the SP register and then transfers a byte from the source operand to the
stack location currently addressed by SP.
– POP transfers a byte operand from the stack location addressed by the SP to the destination
operand and then decrements SP.
Accumulator-Specific Transfers
– XCH exchanges the byte source operand with register A (accumulator).
– XCHD exchanges the low-order nibble of the source operand byte with the low-order nibble
of A.
– MOVX performs a byte move between the external data memory and the accumulator. The
external address can be specified by the DPTR register (16 bit) or the R1 or R0 register (8 bit).
– MOVC moves a byte from program memory to the accumulator. The operand in A is used as
an index into a 256-byte table pointed to by the base register (DPTR or PC). The byte operand
accessed is transferred to the accumulator.
Address-Object Transfer
– MOV DPTR, #data loads 16 bits of immediate data into a pair of destination registers, DPH
and DPL.
9.2.2 Arithmetic
The SAB 80C517 has four basic mathematical operations. Only 8-bit operations using unsigned
arithmetic are supported directly. The overflow flag, however, permits the addition and subtraction
operation to serve for both unsigned and signed binary integers. Arithmetic can also be performed
directly on packed BCD representations.
Addition
– INC (increment) adds one to the source operand and puts the result in the operand.
– ADD adds A to the source operand and returns the result to A.
– ADDC (add with carry) adds A and the source operand, then adds one (1) if CY is set, and
puts the result in A.
– DA (decimal-add-adjust for BCD addition) corrects the sum which results from the binary
addition of two-digit decimal operands. The packed decimal sum formed by DA is returned to
A. CY is set if the BCD result is greater than 99; otherwise, it is cleared.
Semiconductor Group
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