PMC-Sierra, Inc.
PRELIMINARY
PM5381 S/UNI-2488
DATASHEET
PMC-2000489
ISSUE 1
SATURN USER NETWORK INTERFACE FOR 2488 MBIT/S
Register 0752H: TCFP Idle/Unassigned ATM Cell Header
Bit
Type
Function
Default
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
GFC[3]
GFC[2]
0
0
0
0
0
0
0
1
0
1
1
0
1
0
1
0
GFC[1]
GFC[0]
PTI[2]
PTI[1]
PTI[0]
Bit 8
CLP
Bit 7
PAYLD[7]
PAYLD[6]
PAYLD[5]
PAYLD[4]
PAYLD[3]
PAYLD[2]
PAYLD[1]
PAYLD[0]
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PAYLD[7:0]:
The PAYLD[7:0] (Idle Cell Payload) value reflects the payload bytes which will be inserted
into the ATM Idle cell generated by the TCFP.
CLP:
The CLP (Cell Loss Priority) bit contains the eighth bit position of the fourth octet of the
idle/unassigned cell pattern. Cell rate decoupling is accomplished by transmitting idle cells
when the TCFP detects that no outstanding cells are available from the external FIFO and
data is requested on the TCFP egress interface. Additionally, XOFF can be used to force the
transmission of Idle/Unassigned cells in ATM mode.
PTI[2:0]:
The PTI[2:0] (Payload Type) bits contain the fifth, sixth, and seventh bit positions of the fourth
octet of the idle/unassigned cell pattern. Idle cells are transmitted when the TCFP detects
that no outstanding cells are available from the external FIFO and data is requested on the
TCFP egress interface. Additionally, XOFF can be used to force the transmission of
Idle/Unassigned cells in ATM mode.
Proprietary and Confidentail to PMC-Sierra Inc., and for its Customer’s Internal Use
329
PMC [ PMC-SIERRA, INC ]
