tmxf28155 ETC-unknow, tmxf28155 Datasheet - Page 533

• Manufacturer Part Number: tmxf28155
• Description: Tmxf28155 Super Mapper 155/51 Mbits/s Sonet/sdh X28/x21 Ds1/e1
• Manufacturer: ETC-unknow

Preliminary Data Sheet
May 2001
21 28-Channel Framer Block Functional Description
At 19.44 MHz, the parallel bus system interface has 2430 clocks per 8 ms frame. To transfer 84 DS1s or 63 E1s
requires only 2016 clocks. The difference is made up by inserting stuffs onto the bus every so often. Since multiple
devices (three) will drive the bus, the stuff positions are also used to greatly simplify the timing when switching from
one device to another. Both DS1 and E1 use the same general method to drive the bus which is:
21.26.17 Distributed Stuffing: DS1
For DS1, the parallel bus system interface time slot arrangement is as follows:
Six stuff TSs | device 0, link 0—27 | six stuff TSs | device 1, link 0—27 | five* stuff TSs | device 2, link 0—2 |, etc.
Where * means in TSs 1, 5, 9, 13, 17, 21 six stuff time slots are inserted instead of five.
Hence: total time slots = (6 + 28 + 6 + 28 + 5 + 28) * 24 TSs + 6 extra stuff TSs = 2430 TSs.
Agere Systems Inc.
Send some stuffs, then device 0 sends TS0 for link 1 – n, then
Send some stuffs, then device 1 sends TS0 for link 1 – n, then
Send some stuffs, then device 2 sends TS0 for link 1 – n, then
Send some stuffs, then device 0 sends TS1 for link 1 – n, then
Etc.
155/51 Mbits/s SONET/SDH x28/x21 DS1/E1
(continued)
TMXF28155/51 Super Mapper
533