PT7A6632J PERICOM [Pericom Semiconductor Corporation], PT7A6632J Datasheet - Page 10

• Manufacturer Part Number: PT7A6632J
• Description: PT7A6632 32-Channel HDLC Controller
• Manufacturer: PERICOM [Pericom Semiconductor Corporation]

Transmit Bit-Level Processor
The block diagram of the Transmit Bit-Level Processor is
shown in Figure 5. The external memory stores data to be trans-
mitted and the channel operation modes in a set of linked
buffers (referred as Transmit Data/Command Buffers) in the
external memory. Refer to Figure 23 and 24 in the External
Memory Organization and Definition.
For transmit, the PT7A6632 reads the data from external
memory, formats it in HDLC format (generates flags, abort and
idle code, inserts zero-bit, counts the Frame Check Sequences),
non-HDLC signaling format or non-HDLC data format, adapts
data rate, and sends the processed data to TSER output via the
Transmit Interface.
PT019(05/02)
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Figure 6. 32kb/s Subrate Operation - Single Transmit Channel
Figure 5. Block Diagram of Transmit Bit-Level Processor
To/From
Manager
Memory
T1/CEPT PCM-30 Serial Output
MSB
LSB
1 1 1 H G F 1 E 1 1 1 D C B 1 A 1 1 1 Q P O . . .
A B C D E F G H
J K L M N O P Q
1 0 1 1 1 0 0 0
FILL/MASK Pattern
TS m in Frame n
Rate Adapt
(32 Channels)
LSB
Format
&
TS m in Frame n+1
FILL/MASK
Data Bytes to Be Transmitted
10
PT7A6632 32-Channel HDLC Controller
State/Control Signals
Timing
TCLK clocks data bit stream out at its falling edge. TMAX is
multiframe synchronization signal from the T1/E1 trunk inter-
face. SIS decides the TMAX is sampled in rising or falling
edge of TCLK . PT7A6632 processes data channel by channel
for the data transmission under control of channel counter in
the Transmit Interface. See Figure 7-10.
Data Rate Adaptation
The PT7A6632 can adapt the data rate of sub-64kb/s (n x 8kb/
s, n = 1 - 8) to the standard 64kb/s bearer rate. A FILL/MASK
byte in the transmit command buffer is applied to the data bit
by bit to perform data rate adaptation. An example is shown in
the Figure 6.
Transmit
Interface
0 = A fill bit of 1 or high Z (see TSEREN)
1 = Insert bit of data byte starting with LSB
TS m in Frame n+2
TSER
TSEREN
TMAX
TCLK
Transmitted Data
Data Sheet
Ver:2