bt8375kpf Conexant Systems, Inc., bt8375kpf Datasheet - Page 102

• Manufacturer Part Number: bt8375kpf
• Description: Single Chip Transceivers For T1/e1 And Integrated Service Digital Network Isdn Primary Rate Interfaces Systems
• Manufacturer: Conexant Systems, Inc.

2.0 Circuit Description
2.9 Transmit Line Interface Unit
Figure 2-39. Digitized AMI Pulse Shape
2-74
ShapeAddr [060–067]
AMI Pulses
Digitized
8TCKO
TCKO
produces a set of eight 6-bit values which define the pulse shape to be transmitted,
as illustrated in
selected via the Transmit LIU Configuration register [TLIU_CR; addr 068]. The
TLIU control circuit downloads the code values associated with the selected pulse
shape from the ROM to the Transmit Pulse Shape Configuration registers
[SHAPE; addr 060–067], whenever the TLIU register is written to or when the
device is reset. The SHAPE registers can be directly accessed via the
microprocessor interface when a custom pulse shape is desired.
NOTE:
data. The first 4 code values of the pulse (first half of the symbol) are forced to be
positive, and the last 4 values (last half of the symbol) are forced to be negative,
with respect to output pulse polarity.
7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0
The pulse shape block receives P and N rail NRZ data. For each mark, it
The TLIU control circuit converts the 5-bit magnitude to 6-bit 2's complement
Any modification to the TLIU register initiates another download to the
SHAPE registers. The data stored in the pulse shape ROM and the SHAPE
registers is 5-bit magnitude only.
Positive Pulse
Figure
Shape Data
Magnitude
0x00–0x1F
Conexant
2-39. One of eight preprogrammed pulse shapes is
No Pulse
Fully Integrated T1/E1 Framer and Line Interface
Negative Pulse
Bt8370/8375/8376
N8370DSE