Datasheet

C164CI/SI
C164CL/SL
Data Sheet 14 V2.0, 2001-05
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 C164CI’s instructions can be executed
in just one machine cycle which requires 2 CPU clocks (4 TCL). 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’, reduces the execution time of repeatedly performed jumps in a loop
from 2 cycles to 1 cycle.
Figure 4 CPU Block Diagram
MCB02147
CPU
SP
STKOV
STKUN
Instr. Reg.
Instr. Ptr.
Exec. Unit
4-Stage
Pipeline
MDH
MDL
PSW
SYSCON
Context Ptr.
Mul/Div-HW
R15
R0
General
Purpose
Registers
Bit-Mask Gen
Barrel - Shifter
ALU
(16-bit)
Data Page Ptr. Code Seg. Ptr.
Internal
RAM
R15
R0
ROM
16
16
32
BUSCON 0
BUSCON 1
BUSCON 2
BUSCON 3
BUSCON 4 ADDRSEL 4
ADDRSEL 3
ADDRSEL 2
ADDRSEL 1