RELEASED
PM73123 AAL1GATOR-8
DATASHEET
PMC-2000097
ISSUE 2
8 LINK CES/DBCES AAL1 SAR
Also when re-activating a highspeed queue, if it is required that the first
sequence number of the new connection has to be 0, then the queue must be
reset using the A_SW_RESET bit.
Otherwise, clearing and setting the TX_ACTIVE bit in QUEUE_CONFIG can be
used to deactivate and activate the queue.
12.3 UTOPIA Interface Configuration
There is very little setup required to configure the UTOPIA Interface. For typical
operation, the UI_COMN_CFG_REG, UI_SRC_CFG_REG, and
UI_SNK_CFG_REG need to be written to select the mode of operation and the
UI_SRC_ADD_CFG and UI_SNK_ADD_CFG need to be programmed for a pre-
defined address of the device. Once the registers are written with the proper
configuration information, the enable bit should be set to enable normal
operation. The UI_EN bit should be disabled by a chip, which is connected to
the AAL1gator via the UTOPIA/AnyPHY bus, prior to its reset or reconfigured.
This disabling is required to prevent deactivation or reconfiguration in the middle
of a cell transfer.
Aside from the normal configurations, the block can also be placed in loopback
where cells received on the UI interface are transmitted back out onto the UI
interface. The block can be configured to loop all received cells by setting the
U2U_LOOP bit in the UI_COMN_CFG register. Alternately, only cells with a VCI
that matches the VCI contained in U2U_LOOP_VCI register can be looped back
while other cells proceed through normally. The VCI based UI to UI loopback
should be disabled when writing to U2U_LOOP_VCI.
12.4 Special Queue Configuration Modes
12.4.1 AAL0
AAL0 is a null ATM adaptation layer. In this mode, all 48 payload bytes of the
ATM cell contain data. In this mode, there is no data structure, signaling or
sequence number. However, AAL0 mode can be enabled for a queue, which is
mapped to an entire link, or it can be mapped to a single DS0 queue, or it can be
mapped to a group of DS0s.
However, it is important to note that because there is no structure, the AAL0
queue will function as unstructured data. If the queue is a nxDS0 queue, the
data will maintain byte alignment across the ATM network, but the bytes may not
arrive in the same DS0s they were transmitted.
AAL0 mode is enabled by setting AAL0_MODE_ENABLE in the
TRANSMIT_CONFIG memory register in the transmit queue table and by setting
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