HFC-S2M Cologne Chip AG, HFC-S2M Datasheet - Page 95

• Manufacturer Part Number: HFC-S2M
• Description: Isdn HDLC Fifo Controller With Primary Rate Interface
• Manufacturer: Cologne Chip AG

part of the data flow, while the outer circle shows the connection of three data sources and
data drains respectively. The E1 interface have a fixed mapping between HFC-channels and
E1 time slots so that there is no need of a separate E1 time slot numbering.
FIFO: The FIFOs are buffers between the universal bus interface and the PCM and E1
HFC-channel: HFC-channels are used to define data paths between FIFOs on the one
PCM time slot: The PCM data stream is organized in time slots. The number of PCM
E1 time slot: The E1 data stream is organized in time slots. E1 time slots have always the
Each FIFO, HFC-channel and time slot number exist for transmit and receive direction. The
data rate is always 8 kByte/s for every E1 time slot and every PCM time slot. FIFOs, HFC-
channels, E1 time slots and PCM time slots have always a width of 8 bit.
March 2003 (rev. A)
HFC-E1
Figure 3.2: Areas of FIFO oriented, HFC-channel oriented and PCM time slot oriented numbering
interface. The HDLC controllers are located on the non host bus side of the FIFOs.
The number of FIFOs depends on the FIFO size configuration (see Section 4.2) and
starts with number 0. The maximum FIFO number is 31. Furthermore data directions
transmit and receive are associated with every FIFO number.
side and PCM and E1 interface on the other side. The HFC-channels are numbered
0 . . . 31. Furthermore data directions transmit and receive are associated with every
HFC-channel number.
It is important not to mix up the HFC-channels of the here discussed data flow (inner
circle of Figure 3.2) with the B-channels and the D-channel of the E1 interface.
time slots depends on the data rate, i.e. there are 32 time slots (2 MBit/s), 64 time
slots (4 MBit/s) or 128 time slots (8 MBit/s). As data directions transmit and receive
are associated with every time slot number, slots are numbered 0 . . . 15, 0 . . . 31 or
0 . . . 63.
same number and data direction as the associated HFC-channel.
interface
host
numbering
PCM slot
oriented
interface
PCM
oriented numbering
numbering
oriented
FIFO
channel
Data Sheet
Data flow
ISDN applications:
B-channels
D-channel
Cologne
Chip
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