STANDARD PRODUCT
PM5365 TEMAP
DATASHEET
PMC-1991148
ISSUE 3
HIGH DENSITY VT/TU MAPPER
AND M13 MULTIPLEXER
12
OPERATION
12.1 DS3 Frame Format
The TEMAP provides support for both the C-bit parity and M23 DS3 framing
formats. The DS3 frame format is shown in Figure 13.
Figure 17: DS3 Frame Structure
X : X-Bit Channel
x
Sꢀ Transmit: The TEMAP inserts the FERF signal on the X-bits. FERF
generation is controlled by either the FERF bit of the DS3 TRAN
Configuration register or by detection of OOF, RED, LOS and AIS, as
configured by the TEMAP Master DS3 Alarm Enable register.
Sꢀ Receive: The TEMAP monitors the state and detects changes in the state
of the FERF signal on the X-bits.
P : P-Bit Channel
x
Sꢀ Transmit: The TEMAP calculates the parity for the payload data over the
previous M-frame and inserts it into the P1 and P2 bit positions.
Sꢀ Receive: The TEMAP calculates the parity for the received payload. Errors
are accumulated in the DS3 PMON Parity Error Event Count registers.
M : M-Frame Alignment Signal
x
Sꢀ Transmit: The TEMAP generates the M-frame alignment signal (M1 = 0,
M2 = 1, M3 = 0).
Sꢀ Receive: The TEMAP finds M-frame alignment by searching for the F-bits
and the M-bits. Out-of-frame is removed if the M-bits are correct for three
consecutive M-frames while no discrepancies have occurred in the F-bits.
Proprietary and Confidential to PMC-Sierra, Inc. and for its Customers’ Internal Use
148
PMC [ PMC-SIERRA, INC ]
