S/UNI®-8x155 ASSP Telecom Standard Product Data Sheet
Released
Register 0x0C2, 0x1C2, 0x2C2, 0x3C2, 0x4C2, 0x5C2, 0x6C2, 0x7C2:
TXFP Control
Bit
Type
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Function
IPGAP[3]
IPGAP[2]
IPGAP[1]
IPGAP[0]
TIL[3]
TIL[2]
TIL[1]
TIL[0]
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0
0
1
0
0
1
0
0
TIL[3:0]:
The Transmit Initiation Level (TIL[3:0]) bits are used to determine when to initiate a POS
frame transmission. After the channel buffer is emptied, data transmission starts only when
either there is a complete packet or that the number of bytes stored in the channel buffer
equal the value of TIL[3:0] times 16.
Once initiated, the transmission will continue until the packet is transmitted or an underrun
occurs. Before starting another packet, a complete packet must be in the channel buffer or
the buffer fill level must exceed the level specified by TIL[3:0]. When TXFP underruns, the
programmed TIL[3:0] is not adhered to, hence it is recommanded that upon detection of
TXFP underrun the violating Level2 and Level3 channel FIFOs be reset.
Table 12 Transmit Initiation Level Values
TIL[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
FIFO Fill Level
0
TIL[3:0]
1000
1001
1010
1011
1100
1101
1110
1111
FIFO Fill Level
128
144
160
176
192
208
224
240
16
32
48
64
80
96
112
IPGAP[3:0]:
The Inter Packet Gaping (IPGAP[3:0]) bits are used to program the number of Flag
Sequence characters inserted between each POS Frame. These bits can not be dynamically
modified. The programmed value is encoded as indicated in Table 13.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC- 2010299, Issue 2
266
PMC [ PMC-SIERRA, INC ]
