cx28394 Conexant Systems, Inc., cx28394 Datasheet - Page 71

• Manufacturer Part Number: cx28394
• Description: Quad/x16/octal-t1/e1/j1 Framers
• Manufacturer: Conexant Systems, Inc.

CX28394/28395/28398
Quad/x16/Octal—T1/E1/J1 Framers
Table 2-2. Criteria for Loss/Recovery of Receive Framer Alignment
100054E
SF
SLC
FSLOF
ESF
T1DM
Mode
Superframe alignment is recovered when:
During any SF mode, loss of frame alignment (FRED) is declared when:
[RLOFA–RLOFC; addr 040]. FS_NFAS [addr 045] determines whether Fs bits are included in error count.
Superframe alignment is recovered when:
TR-TSY-000008.
During SLC modes without FSLOF , loss of frame alignment (FRED) is declared when:
FSLOF instructs the online framer to monitor 16 of 36 Fs bits (SLC multiframe pattern) for loss of frame
alignment criteria. FS_NFAS [addr 045] must also be set to include Fs bits in loss of frame. FSLOF does not
affect the offline framer's search criteria.
Extended Superframe alignment is recovered when:
without pattern errors.
If there is only one valid FPS candidate and the mode is one of the following:
If there are two or more valid FPS candidates and the mode is one of the following:
During any ESF mode, loss of frame alignment (FRED) is declared when:
Number of FPS pattern errors detected meets selected loss of frame criteria [RLOFA–RLOFC; addr 040].
During T1DM mode, frame alignment is recovered in two steps:
During T1DM mode, loss of frame alignment (FRED) is declared when:
[RLOFA–RLOFC; addr 040]. FS_NFAS [addr 046] does not affect T1DM mode.
NOTE(S):
and reframe criteria = 2 out of 6 F-bit errors [RLOFA–RLOFC; addr 040].
If JYEL, only Ft bits are used, Fs bits are ignored.
If no JYEL, SF pattern (001110) found in Fs bits.
Number of frame errors detected—either Ft or Fs bit errors—meets selected loss of frame criteria
Terminal frame alignment is recovered, identifying Ft bits.
SLC pattern (refer to
Number of Ft bit errors detected meets selected reframe criteria [RLOFA–RLOFC; addr 040].
A valid FPS candidate is located (001011). Candidate bits are each separated by 772 digits and are received
No CRC mode—align to FPS, regardless of CRC6 comparison.
Mimic CRC mode—align to FPS, regardless of CRC6 comparison.
Force CRC mode—align to FPS, only if CRC6 is correct.
No CRC mode—do not align (INVALID status).
Mimic CRC mode—align to first FPS with correct CRC6.
Force CRC mode—align to first FPS with correct CRC6.
Number of frame errors detected, either Ft, Fs, or T1DM errors, meets selected loss of frame criteria
•
•
1. A 6-bit T1DM pattern (10111xx0) is found.
2. A valid F-bit pattern (Ft, Fs, or FPS) is found in the first six consecutive frames of the 12-frame cycle
Terminal frame alignment is recovered, identifying Ft bits.
Depends on SF submode:
aligned to the T1DM pattern.
To be compatible with Bellcore TA-TSY-000278, the processor must select SF + T1DM framer mode
Table A-3, SLC-96 Fs Bit
Conexant
Description
Contents) is found in 16 of 36 Fs bits, according to Bellcore
2.0 Circuit Description
2.2 Receiver
2-13