
28229-DSH-001-B
Mindspeed Technologies
4
-3
CX28224/5/9 Data Sheet
UTOPIA Interfaces
4.3
IMA UTOPIA
This is the normal interface for IMA applications and is selected as shown in
It is intended to interface to a single ATM Layer device and appear as a multi-port
PHY device.
Figure 4-1 illustrates the connections to/from the ATM Layer device.
The number of “ports” or channels on the IMA Subsystem is the sum of the number of
configured IMA groups plus the number of pass-through facilities. The IMA
CX28229 requires a unique Utopia address for each channel (IMA group or pass-
through). There are no restrictions placed on the address assignment and not all 32
locations are normally used.
If only one channel is programmed, (a single IMA group and no pass-through
facilities), then the CX28229 can be compatible with UTOPIA Level 1 by fixing the
address lines to a specific value and setting the IMA group’s ATM address (through
the software driver) to that value.
The CX28229 provides numerous options to match non-standard UTOPIA
controllers. See the IMA_ATM_UTOPIA_BUS_CTL register, 0x413, for more
information.
4.4
TC Block UTOPIA
This interface is selected when using the device as a stand-alone cell delineator. See
interface with the following enhancements.
UDF2 Programmability
The user can program the contents of the UDF2 byte when operating in 16-bit
UTOPIA mode. Be default, the contents of the UDF2 byte (detailed in Table 10-9) on
the receive interface will match the default value of the UTOPIA port address. This
can be changed by writing the desired value to the corresponding UDF2 control
register, 0x0F. Bus width is controlled by bit 5 of the ATMINTFC register.
Port Number Assignment
The UTOPIA address for each port is stored in bits 0–4 of the UTOP2 register (0x0E).
The default for this value is the port number. For example, the UTOP2 register for port
4 (0x10E [with the offset]) defaults to 04 hex. However, the value can be changed to
any value from 00–1E hex by programming the register to accommodate multiple
devices on the same UTOPIA bus. The value 1F hex is reserved for the null address.
The UTOPIA address should be changed only when the device or port is in the reset
state.
NOTE:
0x1F can be assigned as a valid port address to enable 32 port bypass.