Rainbow Electronics DS2152 User Manual

Page 32

DS2152

031897 32/79

LINE CODE VIOLATION COUNTING ARRANGEMENTS Table 5–1

COUNT EXCESSIVE

ZEROS? (RCR1.7)

B8ZS ENABLED?

(CCR2.2)

WHAT IS COUNTED

IN THE LCVCRs

BPVs

yes

BPVs + 16 consecutive zeros

yes

BPVs (B8ZS code words not counted)

yes

BPV’s + 8 consecutive zeros

5.2

Path Code Violation Count Register

(PCVCR)

When the receive side of the DS2152 is set to operate in
the ESF framing mode (CCR2.3=1), PCVCR will auto-
matically be set as a 12–bit counter that will record
errors in the CRC6 code words. When set to operate in
the D4 framing mode (CCR2.3=0), PCVCR will auto-

matically count errors in the Ft framing bit position. Via
the RCR2.1 bit, the DS2152 can be programmed to also
report errors in the Fs framing bit position. The PCVCR
will be disabled during receive loss of synchronization
(RLOS=1) conditions. See Table 5–2 for a detailed
description of exactly what errors the PCVCR counts.

PCVCR1: PATH VIOLATION COUNT REGISTER 1 (Address = 25 Hex)
PCVCR2: PATH VIOLATION COUNT REGISTER 2 (Address = 26 Hex)

(MSB)

(LSB)

(note 1)

CRC/FB11

CRC/FB10

CRC/FB9

CRC/FB8

CRC/FB7

CRC/FB6

CRC/FB5

CRC/FB4

CRC/FB3

CRC/FB2

CRC/FB1

CRC/FB0

SYMBOL

POSITION

NAME AND DESCRIPTION

CRC/FB11

PCVCR1.3

MSB of the 12–Bit CRC6 Error or Frame Bit Error Count (note #2)

CRC/FB0

PCVCR2.0

LSB of the 12–Bit CRC6 Error or Frame Bit Error Count (note #2)

NOTES:

1. The upper nibble of the counter at address 25 is used by the Multiframes Out of Sync Count Register

2. PCVCR counts either errors in CRC code words (in the ESF framing mode; CCR2.3=1) or errors in the fram-

ing bit position (in the D4 framing mode; CCR2.3=0).

PATH CODE VIOLATION COUNTING ARRANGEMENTS Table 5–2

FRAMING MODE

(CCR2.3)

COUNT Fs ERRORS?

(RCR2.1)

WHAT IS COUNTED

IN THE PCVCRs

errors in the Ft pattern

yes

errors in both the Ft & Fs patterns

ESF

don’t care

errors in the CRC6 code words

5.3

MULTIFRAMES OUT OF SYNC COUNT

REGISTER (MOSCR)

Normally the MOSCR is used to count the number of
multiframes that the receive synchronizer is out of sync
(RCR2.0=1). This number is useful in ESF applications
needing to measure the parameters Loss Of Frame

Count (LOFC) and ESF Error Events as described in
AT&T publication TR54016. When the MOSCR is oper-
ated in this mode, it is not disabled during receive loss of
synchronization (RLOS=1) conditions. The MOSCR
has alternate operating mode whereby it will count
either errors in the Ft framing pattern (in the D4 mode) or

PCVCR1

PCVCR2