DS26401 datasheet(102/309 Pages) DALLAS

102 / 309 page

DS26401 Octal T1/E1/J1 Framer

102

8.22 Interfacing the T1 Rx Framer to the BERT

Data from the DS26401 receive framer can be ported to the on-chip BERT by using the registers described below.

Either framed or unframed data can be provided to the BERT, controlled by the RBFUS bit in the RBICR. Any single

DS0 or combination of DS0s can be extracted from the data stream up to the entire T1 payload, as controlled by the

RBCS registers.

Note that one BERT resource is shared among all 8 framers. Therefore, the RBEN bit should be set for only one

framer at a time. If multiple framers have the RBEN bit set, the lower number framer is assigned the resource.

Details concerning the on-chip BERT can be found in Section 12.

RBICR

Receive BERT Interface Control Register

08Ah + (200h x n) : where n = 0 to 7, for Ports 1 to 8

Bit #

Name

—

RBDC

RBFUS

RBEN

Default

Bit 0 / Receive BERT Enable (RBEN)

0 = Receive BERT is not assigned to this framer.

1 = Receive BERT is assigned to this framer.

Bit 1 / Receive BERT Framed/Unframed Select (RBFUS)

0 = The framer does not provide data from the F-bit position (framed).

1 = The framer clocks data from the F-bit position (unframed).

Bit 2 / Receive BERT Direction Control (RBDC)

0 = Receive Path: The BERT receives data from the network side via RPOS and RNEG.

1 = Backplane: The BERT receives data from the system backplane via the TSER pin.

Bits 3–7 / Unused. Must be set = 0 for proper operation.

DS26401 Datasheet(PDF) 102 Page - Dallas Semiconductor