CMX625P4 CMLMICRO [CML Microcircuits], CMX625P4 Datasheet - Page 10

• Manufacturer Part Number: CMX625P4
• Description: ISDN TA POTS Interface
• Manufacturer: CMLMICRO [CML Microcircuits]

ISDN TA POTS Interface
1.5.3
The non-TE mode (Line Card Mode) frame structure consists of up to 8 channels of 4 bytes each repeated
at 8kHz, i.e. 256 bits in 125 s or a data rate of 2048kbps for 8 channel frames. The Data Clock (DCL)
operates at twice the data rate, i.e. 4.096MHz. Figure 4 shows the non-TE mode frame structure.
In non-TE mode the IOM-2 bus time multiplexes data, control and status information for up to eight IOM-2
devices or up to 16 Codec-Filters over a single full duplex interface. The frames are subdivided into 8
channels, with one channel being dedicated to each IOM-2 device or pair of Codecs.
Each device on the IOM-2 bus is assigned a slot address and only transmits to and receives from that time
slot. Pins SA0, SA1 and SA2 on the CMX625 are used to program the Slot Address. Outside the
allocated slot the transmit drivers will be set to high impedance to allow other devices to transmit in their
own time slot. To allow two CMX625 devices to share the same slot a Device Select pin (DS) is made
available. This pin forms part of the Monitor Channel Address Byte along with the Slot Address pins and
allows either of the two devices sharing a slot to be individually addressed. See section 1.5.2, part (ii)
MON Channel Address Byte. This mechanism allows both the B1 and B2 data from the same time slot to
be utilised by different devices.
(v) The ‘Intercommunication Channel’ consists of two 64kbps data channels, labelled IC1 and IC2, and
(vi) The ‘TIC’ (Terminal IC) bus is used for connecting more than one device to the D and C/I0 channels
2001 Consumer Microcircuits Limited
provide additional communications paths between devices other than the layer 1 device (data to and
from the layer 1 device is transferred over the B channels).
in Channel 0. The TIC bus is not used by the CMX625.
Non-Terminal Mode (non-TE)
FSC
DCL
DD, DU = 2048kbps
FSC
DCL
DD
DU
= 4.096MHz
= 8kHz
CH0
CH0
B1
B1
Figure 4 Non-Terminal Mode Frame Structure
CH1
CH1
CH2
CH2
B2
B2
CH3
CH3
M
M
S
B
S
B
125µs
10
MONITOR
MONITOR
CH4
CH4
L
S
B
L
S
B
CH5
CH5
D
C/I
C/I
CH6
CH6
M
R
M
R
M
M
X
X
for analogue lines
for ISDN lines
CH7
CH7
CH0
CH0
CMX625
D/625/2