cx29503 Mindspeed Technologies, cx29503 Datasheet - Page 169

• Manufacturer Part Number: cx29503
• Description: Cx29503 Broadband Access Multiplexer Data Sheet
• Manufacturer: Mindspeed Technologies

CX29503 Data Sheet
0x17—Offline Framer Status (FSTAT)
Each framer contains a single offline framer that acts as a shared resource for both receive and transmit
channels. Current alignment status for receive and transmit channels are reported separately in Alarm Status
registers [ALM1, ALM2; addr: 047, 048]. FSTAT is used primarily for diagnostic purposes to monitor the
progress of an alignment search or to verify the acknowledgment of a processor-generated forced reframe
request. These status bits may only be reported for a very short period of time (i.e., 1 clock cycle) because the
RLOF reframe request may immediately request another offline framer search.
INVALID
FOUND
TIMEOUT
29503-DSH-002-B
—
7
No Candidate—Active-high at the conclusion of a search during which no frame alignment
candidates were located.
Frame Search Successful—Active-high indicates the offline framer located frame alignment
according to the selected receive or transmit framer mode. See
Average Reframe Time (MART). Upon detection of frame alignment, the following occurs:
If the reframe pulse causes the receive time base to align to a position that differs from its
existing alignment, the change-of-frame alignment error counter [COFA; addr: 05A] will
increment. Changes of the transmit frame alignment are not detected.
Framer Search Time-Out—Cleared when the offline framer transitions to its ACTIVE state. If
multiple frame candidates exist over the entire mode-dependent time-out interval (see
12), TIMEOUT is latched active-high. Processor-generated reframe requests (RFORCE or
TFORCE) initiate a single search that extends for up to 24 ms before TIMEOUT. After
reporting TIMEOUT, the offline framer starts another search if the reframe request (RLOF or
TLOF) is active.
—
6
• FOUND goes active high
• RLOF or TLOF is cleared by the online framer (depending on RX/TX direction)
• The offline framer goes inactive (if there are no pending reframe requests)
• The RX, TX, or TSB time base is realigned (depending on RX/TX’s direction and the
0 = search active, aborted, timed out, or found
1 = alignment not found (no candidate)
embedded framing mode)
0 = no candidate: search active, aborted, or timed-out
1 = frame alignment found (one and only one candidate)
0 = no candidate; search active, aborted, or found
1 = framer search time-out (multiple candidates)
NOTE:
—
5
Mindspeed Technologies™
In E1 Receive Framer modes, the offline framer also reports intermediate FRED and
MRED status [ALM3; addr: 049] while searching for FAS and MFAS alignment,
respectively.
INVALID
Preliminary Information
4
FOUND
3
TIMEOUT
2
Table 8-12
ACTIVE
1
for the Maximum
Register Description
RX/TXN
Table 8-
0
8
-
39