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28229-DSH-001-B
Mindspeed Technologies
iii
CX28224/5/9
Inverse Multiplexing for ATM (IMA) Family
The CX2822x family of devices provides system designers with a complete integrated
IMA solution for up to 32 ports. All devices include a Transmission Convergence
block to perform cell delineation, on-board RAM to meet ATM forum requirements
for differential delay compensation and a dual mode (UTOPIA or Serial) PHY layer
interface.
Source code for all required software functions is available from Mindspeed. Since
all processing intensive functions are performed in hardware, they require only
minimal overhead from the system processor.
The TC block is capable of bit level cell delineation, which allows for direct connection
DSL serial data streams without a frame sync pulse. Individual ports can be operated
in a 'pass thru' mode without the IMA overhead.
The CX28229 provides direct connection to 8 serial links or can be expanded to a 32
port IMA using the PHY side UTOPIA bus and external TC devices such as the
RS8228. In addition, an external memory bus allows the differential delay memory to
access up to 2 Mbytes of external RAM.
Functional Block Diagram
PHY
layer
UTOPIA
2
interface
IMA
Engine
Line interface 0
Line interface 1
Line interface 2
Line interface 3
Line interface 4
Line interface 5
Line interface 6
Line interface 7
cell processor
Contr
o
l
Regis
ter
s
IMA clocks
IMA_Sy
s
C
lk
IMA_RefClk
TC Status
Registers
TC Control
Registers
Micro interface
TC
Counters
TX
FIFO
RX
FIFO
ATM
layer
UTOPIA
2
interface
TX
FIFO
RX
FIFO
Micro
Clocks
Mic
roClk
8
KHz
In
O
neSec
IO
Status
Regis
ter
s
JTAG
ATM
LAYER
UTOPIA
INTERFACE
PINS
Ph
y
SID
E
IN
TER
F
AC
E
PIN
S
Internal
256Kx8
SRAM
External Memory Interface
extmemsel pin
Differential Delay
memory interface
Ph
yIn
tFcSe
lPin
Phy
IntF
c
Sel
pin
tied
high
Phy
IntF
c
Sel
pin
tied
low
TC
BL
O
C
K
U
T
O
P
IA
IN
TER
F
AC
E
AT
Mmux
[7,6]
=
10
an
d
Phy
IntF
c
Sel
pin
=
high
AT
Mmux
[7,6]
=
01
AT
Mmux
[7,6]
=
10
low
high
AT
Mmux
[7,6]
=
01
an
d
Phy
IntF
c
Sel
pin
=
Low
1
0
Cl
oc
k
inter
fac
e
OneSec
Rx Block
Tx Block
IMA Block
TC Block
CX28229
TxTRL[0]
TxTRL[1]
Distinguishing Features
!
Complete IMA solution in a single package
" 2 port, CX28224, 17mm BGA
" 4 port, CX28225, 17mm BGA
" 8/32 port, CX28229, 17mm BGA
!
Field tested software available
!
Supports up to 32 ports using external TC
PHYs
!
Up to 16 IMA groups
!
Supports the IMA standard requirements
for 25 ms differential delay with 256K
Internal memory
!
Memory expandable to 2 M bytes via
external bus (CX28229 only)
!
UTOPIA level 2 interfaces
!
Glueless interface to Mindspeed Framers
!
Octet or Bit level cell delineation
!
Variable link data rates (64K–3.072 Mb/s)