DS26502 Maxim Integrated Products, DS26502 Datasheet - Page 39

• Manufacturer Part Number: DS26502
• Description: T1/E1/J1/64KCC BITS Element
• Manufacturer: Maxim Integrated Products

8. T1 FRAMER/FORMATTER CONTROL REGISTERS
The T1 framer portion of the DS26502 is configured via a set of five control registers. Typically, the
control registers are only accessed when the system is first powered up. Once the DS26502 has been
initialized, the control registers will only need to be accessed when there is a change in the system
configuration. There are two receive control registers (T1RCR1 and T1RCR2), two transmit control
registers (T1TCR1 and T1TCR2), and a common control register (T1CCR). Each of these registers is
described in this section.
8.1 T1 Control Registers
Register Name:
Register Description:
Register Address:
Bit #
Name
Default
HW
Mode
Bit 0: Resynchronize (RESYNC). When toggled from low to high, a resynchronization of the receive side framer is initiated.
Must be cleared and set again for a subsequent resync.
Bit 1: Sync Enable (SYNCE)
Bit 2: Sync Time (SYNCT)
Bit 3: Sync Criteria (SYNCC)
Bits 4 and 5: Out Of Frame Select Bits (OOF2, OOF1)
Bit 6: Auto Resync Criteria (ARC)
Bit 7: Unused, must be set = 0 for proper operation.
OOF2
0
0
1
1
0 = auto resync enabled
1 = auto resync disabled
0 = qualify 10 bits
1 = qualify 24 bits
In D4 Framing Mode:
0 = search for Ft pattern, then search for Fs pattern
1 = cross couple Ft and Fs pattern
In ESF Framing Mode:
0 = search for FPS pattern only
1 = search for FPS and verify with CRC6
0 = resync on OOF or RLOS event
1 = resync on OOF only
OOF1
—
7
0
0
0
1
0
1
ARC
T1RCR1
T1 Receive Control Register 1
03h
Out Of Frame Criteria
6
0
0
2/4 frame bits in error
2/5 frame bits in error
2/6 frame bits in error
2/6 frame bits in error
OOF1
5
0
0
OOF2
4
0
0
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SYNCC
3
0
0
SYNCT
2
0
0
DS26502 T1/E1/J1/64KCC BITS Element
SYNCE
1
0
0
RESYNC
0
0
0