HFC-4S Cologne Chip AG, HFC-4S Datasheet - Page 101

• Manufacturer Part Number: HFC-4S
• Description: Isdn HDLC Fifo Controller With 8 (4) Integrated S/t Interfaces
• Manufacturer: Cologne Chip AG

For a given HFC-channel number the belonging S/T-channel is calculated with
In both cases the equivalence
is valid.
3.4 Data flow modes
The internal operation of the channel assigner and the subchannel processor depends on the selected
data flow mode. The three available modes
are described in this section.
3.4.1 Simple Mode
In Simple Mode (SM) only one-to-one connections are possible. That means one FIFO, one S/T-
channel or one PCM time slot can be connected to each other. All combinations except the FIFO-to-
FIFO connection are possible. The number of connections is limited by the number of FIFOs. It is
possible to establish as many connections as there are FIFOs
on the FIFO setup (see Section 4.2).
Simple Mode is selected with V_CSM_MD
The FIFO number is always the same as the HFC-channel number whereas the PCM time slot number
can be chosen independently from the HFC-channel number.
Due to the fixed correspondence between FIFO number and HFC-channel, a pair of transmit and
receive FIFOs is allocated even if a bidirectional data connection between the PCM interface and the
S/T interface is established. Please note that in this case the FIFO must be enabled to enable the data
transmission.
than the maximum FIFO number.
March 2003 (rev. A)
HFC-4S
HFC-8S
5
6
div is the integer division. mod is the division remainder mod
Except PCM-to-PCM connections which do not need a FIFO resource if the involved HFC-channel number is higher
Simple Mode (SM)
Channel Select Mode (CSM)
FIFO Sequence Mode (FSM)
G
The HFC-4S has only four S/T interfaces. For this reason, only HFC-channels
0 . . . 15 are valid and can be used from the S/T interface assigner.
Important !
S/T-channel code
interface number
HFC-channel direction
Data Sheet
Data flow
V_FSM_MD
HFC-channel number div
HFC-channel number mod
S/T-channel direction
´
6
. The actual number of FIFOs depends
¼
in the register R_FIFO_MD.
div
µ £
.
5
Cologne
Chip
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