PM7367 datasheet(249/323 Pages) PMC

249 / 323 page

PM7367 FREEDM-32P32

DATA SHEET

PMC-1991499

ISSUE 2

FRAME ENGINE AND DATA LINK MANAGER

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMER’S INTERNAL USE

235

CEN:

The channelise enable bit (CEN) configures the corresponding transmit link

for channelised operation. TCLK[n] is held quiescent during the T1 framing

bit or the E1 framing byte. Thus, on the first rising edge of TCLK[n] after the

extended quiescent period, a downstream block can sample the m.s.b. of

time-slot 1. When CEN is set low, the corresponding link is unchannelised

and the E1 register bit is ignored. TCLK[n] is gapped during non-data bytes.

The choice between treating all data bits as a contiguous stream with

arbitrary byte alignment or byte aligned to gaps in TCLK[n] is controlled by

the BSYNC bit.

E1:

The E1 frame structure select bit (E1) configures the corresponding link for

channelised E1 operation when CEN is set high. TCLK[n] is held quiescent

during the FAS and NFAS framing bytes. The most significant bit of time-slot

1 is placed on TD[n] on the last falling edge of TCLK[n] ahead of the

extended quiescent period. Link data is present at time-slots 1 to 31. When

E1 is set low and CEN is set high, the corresponding link is configured for

channelised T1 operation. TCLK[n] is held quiescent during the framing bit.

The m.s.b. of time-slot 1 is placed on TD[n] on the last falling edge of

TCLK[n] ahead of the extended quiescent period. Link data is present at

time-slots 1 to 24. E1 is ignored when CEN is set low.

BSYNC:

The byte synchronisation enable bit (BSYNC) controls the interpretation of

gaps in TCLK[n] when the corresponding link is in unchannelised mode (CEN

set low). When BSYNC is set high, the data bit on TD[n] clocked in by a

downstream device on the first rising edge of TCLK[n] after an extended

quiescent period is considered to be the most significant bit of a data byte.

When BSYNC is set low, gaps in TCLK[n] carry no special significance.

BSYNC is ignored when CEN is set high.

PM7367 датащи(PDF) 249 Page - PMC-Sierra, Inc