
XRT79L71
PRELIMINARY
219
1-CHANNEL DS3/E3 CLEAR-CHANNEL FRAMERLIU COMBO - CC/HDLC ARCHITECTURE
REV. P2.0.0
is to support Performance Monitoring and Error Detection within the DS3 data-stream, as it is transported from
one terminal equipment to another.
Processing at the Local Terminal Equipment
The Receive DS3 Framer block will compute and verify the P-bits within each DS3 frame that it receives. If the
Receive DS3 Framer block determines that the P-bits within a given DS3 frame are erred, then it will do the
following.
Generate the Detection of P-bit Error interrupt request, by asserting the Interrupt Output pin (e.g., by pulling
it "Low") and setting Bit 0 (Detection of P-Bit Error Interrupt Status), within the Receive DS3 Interrupt Status
Register, to "1" as illustrated below.
It will increment the PMON P-bit/Parity Error Count Register once for each DS3 frame that is determined to
have erred P-bits. The PMON P-bit/Parity Error Count Register is located at Address = 0x1154 and 0x1155.
The bit-format for each of these registers is presented below.
NOTE: For instructions on how to read out these Performance Monitor Register, please see Section 2.5. It will also increment the One Second - P-bit/Parity Error Count - Accumulator Register once for each DS3
frame, with erred P-bits. detected. The One Second - P-Bit/Parity Error Count -Accumulator Register is
located at Address = 0x1170 and 0x1171. The bit-format for this 16-bit register is presented below.
Receive DS3 Interrupt Status Register (Address = 0x1113)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Detection of
CP Bit Error
Interrupt
Status
Change of
LOS Defect
Condition
Interrupt
Status
Change of
AIS Defect
Condition
Interrupt
Status
Change of
Idle
Condition
Interrupt
Status
Change of
FERF Defect
Condition
Interrupt
Status
Change of
AIC State
Interrupt
Status
Change of
OOF Defect
Condition
Interrupt
Status
Detection of
P-Bit Error
Interrupt
Status
RUR
0
1
PMON Parity/P-Bit Error Count Register - MSB (Address = 0x1154)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
PMON_Parity_Error_Count_Upper_Byte[7:0]
RUR
0
PMON Parity/P-Bit Error Count Register - LSB (Address = 0x1155)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
PMON_Parity_Error_Count_Lower_Byte[7:0]
RUR
0