3.0 Registers
CX28394/28395/28398
3.12 Transmitter Registers
Quad/x16/Octal—T1/E1/J1 Framers
Table 3-18. Criteria for T1 Loss/Recovery of Transmit Frame Alignment
Mode
FT Only
Description
Terminal Frame Alignment is recovered when:
•
One and only one valid Ft pattern (1010) is found in 12 alternate F-bit locations (3 ms), where F-bits
are separated by 193 bits.
Transmit Loss of Frame (TLOF) alignment is declared when:
Number of Ft bit errors detected meets selected loss of frame criteria [TLOFA–TLOFC; addr 071].
•
SF
Superframe alignment is recovered when:
•
•
Terminal frame alignment is recovered, identifying Ft bits.
Depends on SF submode:
If JYEL:
If SF pattern (00111x) found in Fs bits
If no JYEL:
SF pattern (001110) found in Fs bits. Fs errors do not cause Transmit Loss of Frame (TLOF) align-
ment.
Transmit loss of frame alignment (TLOF) declared when:
•
Number of Ft bit errors detected meets selected reframe criteria [TLOFA–TLOFC; addr 071]. Notice
that Fs bit multiframe errors are reported in TMERR [ISR0; addr 00B], but do not cause a loss of
transmit frame alignment.
SLC
Superframe alignment is recovered when:
•
•
Terminal frame alignment is recovered, identifying Ft bits.
SLC pattern (refer to Table A-3, SLC-96 Fs Bit Contents) found in 16 of 32 Fs bits according to
Bellcore TR-TSY-000008.
Fs errors do not cause Transmit Loss of Frame (TLOF) alignment.
Transmit loss of frame alignment (TLOF) declared when:
•
Number of Ft bit errors detected meets selected reframe criteria [TLOFA–TLOFC; addr 071]. Notice
that Fs bit multiframe errors are reported in TMERR [ISR0; addr 00B], but do not cause a loss of
transmit frame alignment.
ESF
Extended superframe alignment is recovered when:
•
Valid FPC candidate located (001011). Candidate bits are each separated by 772 digits and received
without pattern errors:
If only one valid FPS candidate and:
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.
If two or more valid FPS candidates and:
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.
Transmit loss of frame alignment (TLOF) declared when:
•
Number of FPS pattern errors detected meets selected loss of frame criteria [TLOFA–TLOFC;
addr 071].
3-58
Conexant
100054E
CONEXANT [ CONEXANT SYSTEMS, INC ]
