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CN3840-400 EXP - Cavium
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Cavium CN3840-400 EXP
octeon cn38xx.png
General Info
DesignerCavium
ManufacturerTSMC
Model NumberCN3840-400 EXP
Part NumberCN3840-400BG1521-EXP
MarketNetworking
IntroductionAugust 22, 2005 (announced)
August 22, 2005 (launched)
General Specs
FamilyOCTEON
SeriesCN3800
Frequency400 MHz
Microarchitecture
ISAMIPS64 (MIPS)
MicroarchitecturecnMIPS
Core NamecnMIPS
Process130 nm
TechnologyCMOS
Word Size64 bit
Cores8
Threads8
Max CPUs1 (Uniprocessor)
Max Memory16 GiB
Packaging
PackageFCBGA-1521 (BGA)
Ball Count1521
InterconnectBGA-1521

The CN3840-400 EXP is a 64-bit octa-core MIPS communication microprocessor designed by Cavium and introduced in 2005. This processor, which incorporates eight cnMIPS cores, operates at 400 MHz. This processor includes a number of hardware networking accelerators including units for high-performance packet I/O processing, QoS, TCP, and RegEx. This MPU supports up to 16 GiB of DDR2-800 ECC memory.

Cache[edit]

Main article: cnMIPS § Cache

[Edit/Modify Cache Info]

hierarchy icon.svg
Cache Organization
Cache is a hardware component containing a relatively small and extremely fast memory designed to speed up the performance of a CPU by preparing ahead of time the data it needs to read from a relatively slower medium such as main memory.

The organization and amount of cache can have a large impact on the performance, power consumption, die size, and consequently cost of the IC.

Cache is specified by its size, number of sets, associativity, block size, sub-block size, and fetch and write-back policies.

Note: All units are in kibibytes and mebibytes.
L1$320 KiB
0.313 MiB
327,680 B
3.051758e-4 GiB
L1I$256 KiB
0.25 MiB
262,144 B
2.441406e-4 GiB
8x32 KiB64-way set associative 
L1D$64 KiB
0.0625 MiB
65,536 B
6.103516e-5 GiB
8x8 KiB64-way set associativeWrite-through

L2$1 MiB
1,024 KiB
1,048,576 B
9.765625e-4 GiB
  1x1 MiB8-way set associative 

Memory controller[edit]

[Edit/Modify Memory Info]

ram icons.svg
Integrated Memory Controller
Max TypeDDR2-800
Supports ECCYes
Max Mem16 GiB
Controllers1
Channels1
Width128 bit
Max Bandwidth11.92 GiB/s
20.741 GB/s
12,206.08 MiB/s
0.0116 TiB/s
0.0128 TB/s
Bandwidth
Single 11.92 GiB/s

Expansions[edit]

[Edit/Modify Expansions Info]

ide icon.svg
Expansion Options
PCI-X
Width64 bit
Clock133.33 MHz
Rate1,017.25 MiB/s
Featureshost or slave
UART
Ports2

GP I/OYes

Networking[edit]

[Edit/Modify Network Info]

ethernet plug icon.svg
Networking
MII
RGMIIYes (Ports: 8)
SPI
SPI-4.2Yes (Ports: 2)

Hardware Accelerators[edit]

[Edit/Modify Accelerators Info]

hardware accel icon.svg
Hardware Accelerators
RegEx
RegExYes
Features16 Engines
Networking
TCPYes
QoSYes
Compression
CompressionYes
DecompressionYes

Block diagram[edit]

octeon cn38xx block diagram.png

Datasheet[edit]

Has subobject
"Has subobject" is a predefined property representing a container construct and is provided by Semantic MediaWiki.
CN3840-400 EXP - Cavium#package +
base frequency400 MHz (0.4 GHz, 400,000 kHz) +
core count8 +
core namecnMIPS +
designerCavium +
familyOCTEON +
first announcedAugust 22, 2005 +
first launchedAugust 22, 2005 +
full page namecavium/octeon/cn3840-400bg1521-exp +
has ecc memory supporttrue +
has hardware accelerators for data compressiontrue +
has hardware accelerators for data decompressiontrue +
has hardware accelerators for network quality of service processingtrue +
has hardware accelerators for regular expressiontrue +
has hardware accelerators for tcp packet processingtrue +
instance ofmicroprocessor +
isaMIPS64 +
isa familyMIPS +
l1$ size0.313 MiB (320 KiB, 327,680 B, 3.051758e-4 GiB) +
l1d$ description64-way set associative +
l1d$ size0.0625 MiB (64 KiB, 65,536 B, 6.103516e-5 GiB) +
l1i$ description64-way set associative +
l1i$ size0.25 MiB (256 KiB, 262,144 B, 2.441406e-4 GiB) +
l2$ description8-way set associative +
l2$ size1 MiB (1,024 KiB, 1,048,576 B, 9.765625e-4 GiB) +
ldateAugust 22, 2005 +
main imageFile:octeon cn38xx.png +
manufacturerTSMC +
market segmentNetworking +
max cpu count1 +
max memory16,384 MiB (16,777,216 KiB, 17,179,869,184 B, 16 GiB, 0.0156 TiB) +
max memory bandwidth11.92 GiB/s (20.741 GB/s, 12,206.08 MiB/s, 0.0116 TiB/s, 0.0128 TB/s) +
max memory channels1 +
microarchitecturecnMIPS +
model numberCN3840-400 EXP +
nameCavium CN3840-400 EXP +
packageFCBGA-1521 +
part numberCN3840-400BG1521-EXP +
process130 nm (0.13 μm, 1.3e-4 mm) +
seriesCN3800 +
supported memory typeDDR2-800 +
technologyCMOS +
thread count8 +
word size64 bit (8 octets, 16 nibbles) +