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STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
PROPRIETARY AND CONFIDENTIAL
255
Figure 64 shows the function of the various telecom DROP bus signals in AU4
mode. Data on LDDATA [7:0] is sampled on the rising edge of LREFCLK. The
bytes forming the VC4 virtual container are identified by the setting the LDPL
signal high. The LDC1J1V1 signal pulses high, while LDPL is set low, to mark
the single C1 byte in every frame of the AU4 transport envelope. The LDC1J1V1
signal is set high again with LDPL high to mark the J1 byte of the VC4. The bytes
forming the various tributary synchronous payload envelopes are identified by
the LDTPL signal being set high. The LDV5 signal pulses high to mark the V5
bytes of each outgoing tributaries.
Figure 64
- Telecom DROP Bus Timing - AU4 VC
LREFCLK
LDPL
LDC1J1
LDDATA[7:0]
A1 A2 A2 A2 C1 X X
V5 byte TUG3 #1
Z7 byte TUG3 #1
National bytes
V5
J1
V1 V1 V1
V1 byte TU #1,
TUG2 #1, TUG3 #1
NPNP NP
First NPI byte TUG3 #1
J1 byte VC4
Z7
LDTPL
INVALID
LDV5
INVALID
The LDV5 and LDTPL signals are optional when using the ingress VTPP within
the TEMUX which will regenerate the LDV5 and LDTPL signals from LDC1J1V1,
LDPL and the pointers within LDDATA[7:0]. In order to bypass the ingress VTPP,
the position of the single J1 byte and the VC4 is implicitly defined by the C1 byte
position. In the locked AU4 mode, the VC4 is defined to be aligned to the AU4
transport envelope such that the J1 byte occupies the first available payload byte
after the C1 byte, and no pointer justifications are possible.