![](http://datasheet.mmic.net.cn/330000/PM4354-PI_datasheet_16444274/PM4354-PI_367.png)
RELEASED
PM4354 COMET-QUAD
DATASHEET
PMC-1990315
ISSUE 6
FOUR CHANNEL COMBINED E1/T1/J1
TRANSCEIVER / FRAMER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC. AND FOR ITS CUSTOMERS’ INTERNAL USE
352
G6=1
CRC ERROR EVENT
≤
320
SE=1
Severely Errored Framing Event
≥
1(FE shall =0)
FE=1
Frame Synchronization Bit Error Event
≥
1
(SE shall=0 )
LV=1
Line code violation event
≥
1
SL=1
Slip Event
≥
1
LB=1
Payload Loopback Activated
U1,U2=0
Under Study For Synchronization.
R=0
Reserved ( Default Value =0)
NmNI=00,01,10,11
One second Report Modulo 4 Counter
12.7 Using the Transmit Line Pulse Generator
The internal digital-to-analog pulse waveform registers, accessible via the microprocessor bus,
can be used to create a custom waveform. These 120 pulse waveform storage registers are
accessed indirectly through XLPG Pulse Waveform Storage Write Address and XLPG Pulse
Waveform Storage Data register. The values written into the pulse waveform storage registers
correspond to one of 127 quantized levels. 24 samples are output during every transmit clock
cycle.
The waveform being programmed must be done properly in order to meet the various T1 and E1
template specifications. The SCALE[4:0] bits of Line Driver Configuration Register bits are used
to obtain a proper output amplitude.
The following tables contain the waveform values to be programmed for different situations. Table
70 to Table 79 specify waveform values typically used for T1 long haul and short haul
transmission. Table 80 to Table 86 specify waveform values for compliance to the AT&T TR62411
ACCUNET T1.5 pulse template. This is particularly useful where compliance to the jitter
specification of TR62411 is desired. Table 87 and Table 88 specify waveform values for E1
transmission.
Each table describes a waveform that is composed of five columns, representing 5 Unit Intervals
(UIs), or bit periods. At any given time, UI#0 refers to the waveform generated in the current bit
period, UI#1 corresponds to the waveform generated during the previous bit period and UI#2 thru
UI#4 correspond to the waveforms generated in the three bit periods prior to UI#1. The five
columns are conditionally summed together to create the current waveform. Columns are not
added to the current sum if a pulse did not exist in the corresponding UI. This technique allows
each individual waveform to spread over multiple bit periods -- up to 5 bit periods. This is
particularly important in long-haul applications, where the waveform is shaped to concentrate its
energy in the low frequency spectrum, which results in the tails of the pulses being very long.