peb3456 Infineon Technologies Corporation, peb3456 Datasheet - Page 75

• Manufacturer Part Number: peb3456
• Description: Channelized T3 Termination With Ds3 Framer, M13 Multiplexer, T1/ E1 Framers And 256 Channel Hdlc/ppp Controller
• Manufacturer: Infineon Technologies Corporation

channels limit access to system memory for a particular channel. A programmable
transmit buffer size and two programmable threshold are configurable by the host CPU
for each channel.
Note: The sum of both thresholds must be smaller than the transmit buffer size of a
•
Figure 4-8
The threshold values have the following effect:
• Data belonging to one channel stored in the internal transmit buffer will only be
Data Sheet
transferred to the protocol machine when the transmit forward threshold is reached or
if a complete frame is stored inside the transmit buffer. This mechanism avoids data
underrun conditions.
particular channel.
programmable number of
b u f f e r l o c a t i o n s p e r
channel
Transmit Buffer Thresholds
data management unit
transmit forward threshold
transmit refill threshold
protocol machine
transmit buffer
frame
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request new data as long
a s n u m b e r o f e m p t y
l o c a t i o n s i s a b o v e
transmit refill threshold
wa i t wi t h d a t a t r a n s -
mission until buffer level
reaches transmit forward
threshold
Functional Description
PEB 3456 E
05.2001