STANDARD PRODUCT
PM4328 TECT3
DATASHEET
PMC-2011596
ISSUE 1
HIGH DENSITY T1/E1 FRAMER
AND M13 MULTIPLEXER
holding registers and resets the counters to begin accumulating events for the
interval. The counters are reset in such a manner that error events occurring
during the reset are not missed. If the holding registers are not read between
successive transfer clocks, an OVERRUN register bit is asserted.
Generation of the transfer clock within the TECT3 chip is performed by writing to
any counter register location or by writing to the Global PMON Update register.
The holding register addresses are contiguous to facilitate faster polling
operations.
9.4 Bit Oriented Code Detector (RBOC)
The Bit Oriented Code detection function is provided by the RBOC block. This
block detects the presence of 63 of the possible 64 bit oriented codes
transmitted in the T1 Facility Data Link channel in ESF framing format, as
defined in ANSI T1.403 and in TR-TSY-000194 or in the DS3 C-bit parity far-end
alarm and control (FEAC) channel. The 64Th code (111111) is similar to the
HDLC flag sequence and is used by the RBOC to indicate no valid code
received.
Bit oriented codes are received on the Facility Data Link channel or FEAC
channel as a 16-bit sequence consisting of 8 ones, a zero, 6 code bits, and a
trailing zero (111111110xxxxxx0). BOCs are validated when repeated at least 10
times. The RBOC can be enabled to declare a received code valid if it has been
observed for 8 out of 10 times or for 4 out of 5 times, as specified by the AVC bit
in the RBOC Configuration/Interrupt Enable register. The RBOC declares that
the code is removed if two code sequences containing code values different from
the detected code are received in a moving window of ten code periods.
Valid BOC are indicated through the RBOC Interrupt Status register. The BOC
bits are set to all ones (111111) if no valid code has been detected. An interrupt
is generated to signal when a detected code has been validated, or optionally,
when a valid code goes away (i.e. the BOC bits go to all ones).
9.5 HDLC Receiver (RDLC)
The RDLC is a microprocessor peripheral used to receive HDLC frames on the
4kHz ESF facility data link, the E1 Sa-bit data link, the DS3 C-bit parity Path
Maintenance Data Link or a specified channel within a T1 or E1 stream.
The RDLC detects the change from flag characters to the first byte of data,
removes stuffed zeros on the incoming data stream, receives packet data, and
calculates the CRC-CCITT frame check sequence (FCS).
PROPRIETARY AND CONFIDENTIAL
63
PMC [ PMC-SIERRA, INC ]
