
XRT7250
DS3/E3 FRAMER IC
á
REV. 1.1.1
192
Whenever the Receive DS3 Framer block declares
OOF after being in the In-Frame State the following
will happen.
The Receive DS3 Framer will assert the RxOOF
output pin (e.g., toggles it "High").
Bit 4 (RxOOF) within the Rx DS3 Configuration and
Status Register will be set to "1" as depicted below.
Rx DS3 Configuration and Status Register, (Address
= 0x10)
The Receive DS3 Framer block will also issue a
Change in OOF Status interrupt request, anytime
there is a change in the OOF status.
4.3.2.3
Forcing a Reframe via Software Com-
mand
The Framer IC permits the user to force a reframe
procedure of the Receive DS3 Framer block via soft-
ware command. If the user writes a "1" into Bit 0 the
I/O Control Register, as depicted below, then the Re-
ceive DS3 Framer will be forced into the Frame Acqui-
sition Mode, (or more specifically, in the F-Bit Search
Framer block will begin its search for valid F-Bits. The
Framer IC will also respond to this command by as-
serting the RxOOF output pin, and generating a
Change in OOF Status interrupt.
4.3.2.4
Performance Monitoring of the Receive
DS3 Framer block
The user can monitor the number of framing bit errors
(M and F bits) that have been detected by the Re-
ceive DS3 Framer block. This is accomplished by pe-
riodically reading the PMON Framing Bit Error Count
Registers (Address = 0x52 and 0x53), as depicted
below.
When the P/C reads these registers, it will read in
the number of framing bit errors that have been de-
tected since the last read of these two registers.
These registers are reset upon read.
4.3.2.5
DS3 Receive Alarms
RX DS3 CONFIGURATION AND STATUS REGISTER, (ADDRESS = 0X10)
BIT 7BIT 6BIT 5
BIT 4BIT 3BIT2BIT 1BIT 0
RxAIS
RxLOS
RxIdle
RxOOF
Int LOS
Disable
Framing on
Parity
F-Sync Algo
M-Sync Algo
R/O
R/W
XX
X
XXX
XX
I/O CONTROL REGISTER (ADDRESS = 0X01)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT2BIT 1
BIT 0
Disable
TxLOC
LOC
Disable
RxLOC
AMI/ZeroSup*
Unipolar/
Bipolar*
TxLine CLK
Invert
RxLine CLK
Invert
Reframe
R/W
RO
R/W
10
100
00
0
PMON FRAMING BIT ERROR EVENT COUNT REGISTER - MSB (ADDRESS = 0X52)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT2BIT 1BIT 0
F-Bit Error Count - High Byte
RO
10
100
000
PMON FRAMING BIT ERROR EVENT COUNT REGISTER - LSB (ADDRESS = 0X53)
BIT 7BIT 6BIT 5BIT 4BIT 3BIT2BIT 1BIT 0
F-Bit Error Count - Low Byte
RO
00
000