NS32CG16-10 Datasheet, PDF (6/82 Pages) National Semiconductor (TI) – High-Performance Printer / Display Processor

1 0 Product Introduction
The NS32CG16 is a high speed CMOS microprocessor in
the Series 32000 EP family
The NS32CG16 is software-compatible with all other CPUs
in the family
The device incorporates all of the Series 32000 advanced
architectural features with the exception of the virtual mem-
ory capability
Brief descriptions of the NS32CG16 features that are
shared with other members of the family are provided be-
low
Powerful Addressing Modes Nine addressing modes
available to all instructions are included to access data
structures efficiently
Data Types The architecture provides for numerous data
types such as byte word doubleword and BCD which may
be arranged into a wide variety of data structures
Symmetric Instruction Set While avoiding special case
instructions that compilers can’t use the Series 32000 fami-
ly incorporates powerful instructions for control operations
such as array indexing and external procedure calls which
save considerable space and time for compiled code
Memory-to-Memory Operations The Series 32000 CPUs
represent two-address machines This means that each op-
erand can be referenced by any one of the addressing
modes provided
This powerful memory-to-memory architecture permits
memory locations to be treated as registers for all useful
operations This is important for temporary operands as well
as for context switching
Large Uniform Addressing The NS32CG16 has 24-bit
address pointers that can address up to 16 megabytes with-
out any segmentation this addressing scheme provides
flexible memory management without add-on expense
Modular Software Support Any software package for the
Series 32000 architecture can be developed independent of
all other packages without regard to individual addressing
In addition ROM code is totally relocatable and easy to
access which allows a significant reduction in hardware and
software cost
Software Processor Concept The Series 32000 architec-
ture allows future expansions of the instruction set that can
be executed by special slave processors acting as exten-
sions to the CPU This concept of slave processors is
unique to the Series 32000 architecture It allows software
compatibility even for future components because the slave
hardware is transparent to the software With future ad-
vances in semiconductor technology the slaves can be
physically integrated on the CPU chip itself
To summarize the architectural features cited above pro-
vide three primary performance advantages and character-
istics
 High-Level Language Support
 Easy Future Growth Path
 Application Flexibility
1 1 NS32CG16 SPECIAL FEATURES
In addition to the above Series 32000 features the
NS32CG16 provides features that make the device ex-
tremely attractive for a wide range of applications where
graphics support low chip count and low power consump-
tion are required
The most relevant of these features are the graphics sup-
port capabilities that can be used in applications such as
printers CRT terminals and other varieties of display sys-
tems where text and graphics are to be handled
Graphics support is provided by eighteen instructions that
allow operations such as BITBLT data compression expan-
sion fills and line drawing to be performed very efficiently
In addition the device can be easily interfaced to an exter-
nal BITBLT Processing Unit (BPU) for high BITBLT perform-
ance
The NS32CG16 allows systems to be built with a relatively
small amount of random logic The bus is highly optimized
to allow simple interfacing to a large variety of DRAMs and
peripheral devices All the relevant bus access signals and
clock signals are generated on-chip The cycle extension
logic is also incorporated on-chip
The device is fabricated in a low-power CMOS technology
It also includes a power-save feature that allows the clock
to be slowed down under software control thus minimizing
the power consumption This feature can be used in those
applications where power saving during periods of low per-
formance demand is highly desirable
The power save feature and the Bus Characteristics are
described in the ‘‘Functional Description’’ section A general
overview of BITBLT operations and a description of the
graphics support instructions is provided in Section 2 5 De-
tails on all the NS32CG16 instructions can be found in the
NS32CG16 Printer Display Processor Programmer’s Refer-
ence Supplement
6