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MT9072
Data Sheet
88
Zarlink Semiconductor Inc.
13.2 E1 Error Counters
The MT9072 has eight error counters, which can be used for maintenance testing, and ongoing measurement of
the quality of a PCM30 link and to assist the designer in meeting specifications such as ITU-T I.431 and G.821. All
counters can be preset or cleared by writing to the appropriate locations. In addition, four error count latches are
provided which latch the counter data coincident with the one second status bit. Counters can automatically be
cleared (ACCLR register address Y03) after their data is latched. Associated with each counter is a maskable event
indication interrupt and a maskable counter overflow interrupt. Overflow interrupts are useful when cumulative error
counts are being recorded. For example, every time the frame error counter overflow (FEO) interrupt occurs, 256
frame errors have been received since the last FEO interrupt. The interrupt status register bits are cleared when
read. All non-latched error counters are cleared and by programming the counter clear bit (CNCLR register address
Y03) low to high. See Table 43 for counter events and relationship between the counters.
Register
Address
Register
Description
Y03
DL,CCS,CAS and other
Control Register
The CNCLR bit can be used to clear the non-latched counters.
the ACCLR can be used to automatically clear 1 sec counter.
Y15
PRBS Error Counter and
CRC-4 Multiframe Counter
PRBS counts bit errors and the CRC counter interval for each
received multiframe.
Y16
Loss of basic frame counter
Counter that is incremented once per 125 usec whenever bsync
is 1.
Y17
E-bit error counter
This counter counts the ebit errors.
Y18
Bipolar violation counter. This
counter counts the bipolar
violation outside the HDB3
coding.
This counter counts the bipolar violation outside the HDB3
coded zeros.
Y19
CRC-4 error counter
This counter is incremented for calculated crc-4 errors (CRCS1
and CRCS2).
Y1A
FAS bit error counter and FAS
error counter
This counter counts the FAS bit error and FAS errors.
Y28
E bit error counter latch
This counter is the one second latched version of Y17.
Y29
BPV error counter latch
This counter is a one second latched version of Y18.
Y2A
CRC-4 error counter latch
This counter is a one second latched version of Y19.
Y2B
FAS error counter latch
This counter is a one second latched version of Y1A.
Y36
CAS,National, CRC-4 local
and timer interrupt status
register
Oneseci is the one second interrupt status. This interrupt can be
used for performance monitoring.
Y46
CAS,National, CRC-4 local
and timer interrupt mask
register
Onesecm is the one second interrupt status. This interrupt can
be used for performance monitoring.
Table 42 - Registers Required for Observing and Clearing Error Counters (E1)