DS33R41 Maxim Integrated Products, DS33R41 Datasheet - Page 72

• Manufacturer Part Number: DS33R41
• Description: Network Controller & Processor ICs Inverse-Multiplexing Ethernet Mapper wit
• Manufacturer: Maxim Integrated Products

10.5 E1 Framer/Formatter Control and Status
The E1 framer portion of the transceiver is configured by a set of four control registers. Typically, the control
registers are only accessed when the system is first powered up. Once the device has been initialized, the control
registers need only to be accessed when there is a change in the system configuration. There are two receive
control registers (TR.E1RCR1 and TR.E1RCR2) and two transmit control registers (TR.E1TCR1 and TR.E1TCR2).
There are also four status and information registers. Each of these eight registers is described in this section.
Table 10-3. E1 Sync/Resync Criteria
MULTIFRAME
FRAME OR
LEVEL
CRC4
CAS
FAS
FAS present in frame N and
N + 2; FAS not present in
frame N + 1
Two valid MF alignment
words found within 8ms
Valid MF alignment word
found and previous time slot
16 contains code other than
all 0s
DS33R41 Inverse-Multiplexing Ethernet Mapper with Quad Integrated T1/E1/J1 Transceivers
SYNC CRITERIA
72 of 335
Three consecutive incorrect
FAS received
Alternate: (TR.E1RCR1.2 = 1)
The above criteria is met or
three consecutive incorrect bit
2 of non-FAS received
915 or more CRC4 code words
out of 1000 received in error
Two consecutive MF alignment
words received in error
RESYNC CRITERIA
4.2 and 4.3.2
ITU SPEC.
G.706
G.706
G.732
4.1.1
4.1.2
5.2