A80960CF-40, -33, -25, -16
PRELIMINARY 3
The processor also integrates four complete data-
chaining DMA channels and a high-speed interrupt
controller on-chip. DMA channels perform single-
cycle or two-cycle transfers, data packing and
unpacking and data chaining. Block transfers — in
addition to source or destination synchronize d trans-
fers — are supported.
The interrupt contro ller provides full programmability
of 248 interrupt sources int o 32 priority levels with a
typical interrupt tas k switch (lat ency) time of 62 5 ns .
2.1 The 80960C-Series Core
The C-Series core is a very high performance
microarchitect ural im p lementation of th e 80960 Cor e
Architecture. This core can sustain execution of two
instructions per clock (80 MIPS at 40 MHz). To
achieve this level of performance, Intel has incorpo-
rated state-of-the-art silicon technology and innova-
tive microarchitectural constructs into the C-Series
core implementation. Factors that contribute to the
core’s performance include:
• Parallel instruction decoding allows issuance of up
to three instructions per clock
• Single-clock execution of most instructions
• Parallel instruction decode allows sustained,
simultaneous execution of two single-clock instruc-
tions every clock cyc le
• Efficient instruction pipeline minimizes pipeline
break losses
• Register and resource scoreboarding allow simul-
taneous multi-clock instruction execution
• Branch look-ahead and prediction a llows many
branches to execute with no pipeline break
• Local Register Cache integrated on-chip caches
Call/Return context
• Two-way set associative, 4 Kbyte integr ated
instruction cac he
• 1 Kbyte integrated Data RAM sustains a four-word
(128-bit) access every clock cycle
• Direct mapped, 1 Kbyte data cache, write through,
write allocate
2.2 Pipelined, Burst Bus
A 32-bit high performance bus controller interfaces
the 80960CF to external memory and peripherals.
The Bus Control Unit features a maximum transfer
rate of 160 Mbytes per second (at 40 MHz). Inter-
nally programmable wait states and 16 separately
configurable memory regions allow the processor to
interface with a variety of memory subsystems with a
minimum of system complexity and a maximum of
performance. The Bus Control Unit’s main features
include:
• Demultiplexed, burst bus to exploit most efficient
DRAM access modes
• Address pipelining to reduce memory cost while
maintaining performance
• 32-, 16- and 8-bit modes for I/O interfacing ease
• Full internal wait state generation to reduce system
cost
• Little and Big Endian support to ease application
development
• Unaligned access support for code portability
• Three-deep request queue to decouple the bus
from the core
2.3 Instruction Set Summary
Table 1 summarizes the 80960CF instruction set by
logical groupings. See the
i960
®
Cx Microprocessor
User’s Manual
(270710) for a complete description
of the instruction set .
2.4 Flexible DMA Controller
A four-channel DMA controller provides high speed
DMA control for data transfers involving peripherals
and memory. The DMA provides advanced features
such as data chaining, byte assembly and disas-
sembly and a high perform ance fly-by mode ca pable
of transfer s peeds of up to 71 Mbytes per second at
40 MH z. The DMA c ontr oller feat ures a p erfor mance
and flexibility which is only possible by integrating
the DMA controller and the 80960CF core .