SAB-C165 SIEMENS [Siemens Semiconductor Group], SAB-C165 Datasheet - Page 12

• Manufacturer Part Number: SAB-C165
• Description: C16x-Family of High-Performance CMOS 16-Bit Microcontrollers
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

C165
Central Processing Unit (CPU)
The main core of the CPU consists of a 4-stage instruction pipeline, a 16-bit arithmetic and logic unit
(ALU) and dedicated SFRs. Additional hardware has been spent for a separate multiply and divide
unit, a bit-mask generator and a barrel shifter.
Based on these hardware provisions, most of the C165’s instructions can be executed in just one
machine cycle which requires 100 ns at 20-MHz CPU clock. For example, shift and rotate
instructions are always processed during one machine cycle independent of the number of bits to
be shifted. All multiple-cycle instructions have been optimized so that they can be executed very fast
as well: branches in 2 cycles, a 16
16 bit multiplication in 5 cycles and a 32-/16 bit division in
10 cycles. Another pipeline optimization, the so-called ‘Jump Cache’, allows reducing the execution
time of repeatedly performed jumps in a loop from 2 cycles to 1 cycle.
Figure 5
CPU Block Diagram
Semiconductor Group
11