SAB80C517 Datasheet, PDF (35/61 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller

SAB 80C517/80C537
Multiplication/Division Unit
This on-chip arithmetic unit provides fast 32-bit division, 16-bit multiplication as well as shift and
normalize features. All operations are integer operations.
Operation
32-bit/16-bit
16-bit/16-bit
Result
32-bit
16-bit
16-bit ∗ 16-bit
32-bit normalize
32-bit
–
32-bit shift left/right –
1) _{1 tcy = 1 µs @ 12 MHz oscillator frequency.}
2) _{The maximal shift speed is 6 shifts/cycle.}
Remainder
16-bit
16-bit
–
–
–
Execution Time
6 t _cy ¹)
4 t _cy
4 t _cy
6 t _cy ²)
6 t _cy ²)
The MDU consists of six registers used for operands and results and one control register.
Operation of the MDU can be divided in three phases:
Figure 10
Operation of the MDU
To start an operation, register MD0 to MD5 (or ARCON) must be written to in a certain
sequence according to table 5 or 6. The order the registers are accessed determines the type
of the operation. A shift operation is started by a final write operation to register ARCON (see
also the register description).
Semiconductor Group
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