CN8236EBGB Mindspeed Technologies, CN8236EBGB Datasheet - Page 300

• Manufacturer Part Number: CN8236EBGB
• Description: ATM SAR 155Mbps 3.3V ABR/CBR/GFR/UBR/VBR 388-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of CN8236EBGB

• Package: 388BGA
• Traffic Class: ABR|CBR|GFR|UBR|VBR
• Utopia Type: Level 1|Level 2
• Host Interface: PCI
• Maximum Data Rate: 155 Mbps
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3 V

12.0 ATM UTOPIA Interface
12.4 UTOPIA Level 2 Interface
12.4.3 UTOPIA Level 2 Multi-Port Operation
12-10
NOTE:
bus, its port address must be programmed into the SLAVE_ADDR bits of
Config1. Software must be aware that all CN8236s on the bus default to the same
address, (00), and therefore, must reprogram each device to a unique value.
The CN8236 supports multi-port (up to eight) operations as described in the
UTOPIA Level 2 Specification af-phy-0039.000 (see the ATM forum web site for
details: www.atmforum.com). Two primary functions are involved in transferring
data on the UTOPIA bus: polling the ports to determine which ones have data
ready and then selecting which port transfers its data. The receive side is
discussed below. Refer to the above referenced web page for more details.
in the CONFIG1 register. Polling is accomplished by outputting the desired port
number on the UTOPIA address bus. If that port has data ready it asserts the
RxClav line. The controller can ignore this line and continue polling other ports
or it can initiate the data transfer by holding the port address on the address lines
while RxEnb* is deasserted. Once the data transfer has begun, the CN8236 can
continue polling other ports.
diagram assumes that 8 ports are present. At clock cycle a, port 5 has just been
polled. It asserts the RxClav line to indicate that it has a complete cell to send.
The CN8236 continues to poll ports 6 and 7 (both indicate that they do not have
cells at this time). During this entire polling operation, data is being transferred
across the data bus.
bus but this time has raised the TxEnb* line. This selects port 5. Port 5
acknowledges that it is ready by again asserting RxClav. Port 5 then asserts the
RxSOC line and begins to transfer data.
Slave address: When the CN8236 is configured as a slave on the UTOPIA
The CN8236 starts by polling port 0 and continue to NUM_PORTS as stored
The polling and selection process waveforms are shown in
At clock cycle b, the CN8236 has again output port 5 on the UTOPIA address
Number of ports on the bus: When running in multi-port mode the total
number of ports to poll is programmed into the NUM_PORTS bits of
Config1.
Since port numbering begins with 0, this value equals –1 (total number of
ports).
Mindspeed Technologies
ATM ServiceSAR Plus with xBR Traffic Management
™
Figure
28236-DSH-001-B
12-1. This
CN8236