TNETA1585

ATM TRAFFIC MANAGEMENT SCHEDULER DEVICE

WITH RECEIVE UTOPIA AND COPROCESSOR INTERFACES

SDNS041A – NOVEMBER 1996 – REVISED JULY 1998

12

POST OFFICE BOX 655303

transmitted-cell-indication interface (TCCX)

A single-bit interface allows the TNETA1575 to signal to the TNETA1585 that a cell will be transmitted on a

particular channel. This interface can be used to facilitate statistics processing in the TNETA1585 and to aid

in ATM Forum ABR scheduling. When the TNETA1575 determines that it has the data to send a cell, it

simultaneously sends an 18-bit frame to the TNETA1585 that is formatted as follows. The information reflected

by this interface confirms the information reflected in the next-cell register, if the TNETA1575 is transmitting a

TNETA1585 scheduled cell.

CHANNEL

NUMBER

CLP

INDICATOR

CELL TYPE

SCHEDULING

SOURCE

SEND

ACKNOWLEDGE

FRAMING

BIT

17–7

6

5–3

2

1

0

Bits 17–7 (channel number). These bits indicate which one of the 2K channels transmitted the last cell.

Bit 6 (CLP). This field contains the cell-loss-priority indication that was inserted in the outgoing cell’s header.

Bits 5–3 (cell type). This field indicates what type of cell was sent. This field, along with the CLP bit, indicates

the origin of the cell sent. Details are provided in Table 3.

Table 3. TCCX Cell-Type Definition

CLP

CELL TYPE

INDICATION

CLP

BIT 2

BIT 1

BIT 0

INDICATION

0

0

0

0

In-rate VC-level RM cell from RM-cell-contents FIFO A

0

0

0

1

In-rate VC-level RM cell from RM-cell-contents FIFO B

0

0

1

0

In-rate data cell

0

0

1

1

Reserved

0

1

0

0

In-rate VP-level RM cell from RM-cell-contents FIFO A

0

1

0

1

In-rate VP-level RM cell from RM-cell-contents FIFO B

0

1

1

0

Reserved

0

1

1

1

Reserved

1

0

0

0

Out-of-rate VC-level RM cell from RM-cell-contents

FIFO C

1

0

0

1

Out-of-rate VC-level RM cell from RM-cell-contents

FIFO D

1

0

1

0

Out-of-rate data cell

1

0

1

1

Reserved

1

1

0

0

Out-of-rate VP-level RM cell from RM-cell-contents

FIFO C

1

1

0

1

Out-of-rate VP-level RM cell from RM-cell-contents

FIFO D

1

1

1

0

Reserved

1

1

1

1

Reserved

Bit 2 (scheduling source). This bit indicates whether the cell was scheduled directly from the TNETA1575

scheduler table or if it was scheduled by the TNETA1585. This bit is encoded as follows:

BIT 2

INDICATION

0

Scheduler-table scheduled cell

1

TNETA1585 scheduled cell