TXC-04252AIPQ Transwitch Corporation, TXC-04252AIPQ Datasheet - Page 74

• Manufacturer Part Number: TXC-04252AIPQ
• Manufacturer: Transwitch Corporation

Specifications of TXC-04252AIPQ

• Pin Count: 160
• Screening Level: Industrial
• Package Type: PQFP
• Lead Free Status / Rohs Status: Not Compliant

Ed. 3, December 2000
QE1M
TXC-04252
TXC-04252-MB
POINTER LEAK RATE CALCULATIONS
Notes:
1. The procedure described in Notes 2 through 8 below must be performed independently for each of the four ports of the
2. The procedure shown in the diagram above uses a ten-second sliding window with a resolution of one second.
3. The initial FIFO Leak Rate Register value (in memory map address 049H, 079H, 0A9H or 0D9H) must first be set to 04
4. Measure ten consecutive one-second samples from the Positive and Negative Stuff Counters being used. Store all ten
5. Calculate the leak rate (L.R.) using the following equation:
6. Set the FIFO Leak Rate Register (address 049H, 079H, 0A9H or 0D9H) with the value between 4 and 255 calculated
7. Recalculate the value of 'C' by subtracting the oldest sample and adding the newest, and calculate a new leak rate, as
8. Continue to repeat the steps described in Notes 5, 6 and 7 until AIS, LOP, LOS or NDF is received or until you reset the
QE1M device.
Hex.
difference values, i.e.,
There are eight pairs of stuff counters in the QE1M; care should be taken to use the pair appropriate to the programmed
configuration of the device. The counters are located at addresses 032H, 062H, 092H, 0C2H (A side) and 03CH, 06CH,
09CH, 0CCH (B side).
above, then take another one-second sample (e.g., S11).
described in Note 5 (e.g., using S2 through S11).
QE1M.
S1 = POS STUFF COUNT1 - NEG STUFF COUNT1,
S2 = POS STUFF COUNT2 - NEG STUFF COUNT2, and so on through
S10 = POS STUFF COUNT10 - NEG STUFF COUNT10.
L.R. = Hex[ Int [ 280 / C ] ], where
C = ABS [ S1 + S2 + ... + S10 ].
Then, if L.R. < 4, let L.R. = 4,
or if L.R. > 255, let L.R. = 255.
Proprietary TranSwitch Corporation Information for use Solely by its Customers.
Start
Leak Rate
to 04 Hex
Set FIFO
(Note 3)
AIS, LOP
LOS, NDF
or RESET
DATA SHEET
Add Newest
Subt Oldest
1 Second,
Measure
add to C
(Note 4)
(Note 7)
10 SEC
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10 SEC
Leak Rate
Leak Rate
Calculate
1 Second
Set FIFO
Measure
(Note 5)
(Note 6)
(Note 6)
FIFO