Rainbow Electronics DS26504 - Manual (Page 39)

DS26504 T1/E1/J1/64KCC BITS Element
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8. T1 FRAMER/FORMATTER CONTROL REGISTERS
The T1 framer portion of the DS26504 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 DS26504 has been
initialized, the control registers 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:
T1RCR1
Register Description: T1 Receive Control Register 1
Register Address: 03h
Bit
# 7 6 5 4 3 2 1 0
Name — ARC OOF1 OOF2 SYNCC SYNCT SYNCE RESYNC
Default 0 0 0 0 0 0 0 0
HW
Mode
0 0 0 0 0 0 0 0
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)
0 = auto resync enabled
1 = auto resync disabled
Bit 2: Sync Time (SYNCT)
0 = qualify 10 bits
1 = qualify 24 bits
Bit 3: Sync Criterion (SYNCC)
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
Bits 4 and 5: Out-of-Frame Select Bits (OOF2, OOF1)
OOF2 OOF1
OUT-OF-FRAME
CRITERION
0 0 2/4 frame bits in error
0 1 2/5 frame bits in error
1 0 2/6 frame bits in error
1 1 2/6 frame bits in error
Bit 6: Auto Resync Criterion (ARC)
0 = resync on OOF or RLOS event
1 = resync on OOF only
Bit 7: Unused, must be set = 0 for proper operation.