Datasheet

DS21352/DS21552

53 of 137

8.3 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 operated 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 errors in the FPS framing pattern (in the ESF mode). When the

MOSCR is operated in this mode, it is disabled during receive loss of synchronization (RLOS = 1)

conditions. See Table 8-3 for a detailed description of what the MOSCR is capable of counting.

MOSCR1: MULTIFRAMES OUT OF SYNC COUNT REGISTER 1 (Address = 25

Hex) see note 1

MOSCR2: MULTIFRAMES OUT OF SYNC COUNT REGISTER 2 (Address = 27

Hex)

(MSB) (LSB)

MOS/FB1

MOS/FB9 MOS/FB8 (note 1) (note 1) (note 1) (note 1) MOSCR1

CRC/FB7 CRC/FB6 CRC/FB5 CRC/FB4 CRC/FB3 CRC/FB2 CRC/FB1 CRC/FB0 MOSCR2

SYMBOL POSITION NAME AND DESCRIPTION

MOS/FB11 MOSCR1.7 MSB of the 12–Bit Multiframes Out of Sync or F–Bit Error Count (note #2)

MOS/FB0 MOSCR2.0 LSB of the 12–Bit Multiframes Out of Sync or F–Bit Error Count (note #2)

NOTES:

1. The lower nibble of the counter at address 25 is used by the Path Code Violation Count Register

2. MOSCR counts either errors in framing bit position (RCR2.0=0) or the number of multiframes out of sync (RCR2.0=1)

Table 8-3 MULTIFRAMES OUT OF SYNC COUNTING ARRANGEMENTS

FRAMING MODE

(CCR2.3)

COUNT MOS OR F–BIT

ERRORS

(RCR2.0)

WHAT IS COUNTED

IN THE MOSCRs

D4 MOS number of multiframes out of sync

D4 F–Bit errors in the Ft pattern

ESF MOS number of multiframes out of sync

ESF F–Bit errors in the FPS pattern