CX28344 Conexant, CX28344 Datasheet - Page 57

• Manufacturer Part Number: CX28344
• Description: (CX2834x) Dual / Triple / Quad / Hex / Octal - Enhanced DS3 / E3 Framer
• Manufacturer: Conexant

CX28342/3/4/6/8 Data Sheet
2.1.1
Table 2-1. Overhead Sourcing Methods (1 of 2)
28348-DSH-001-B
DS3
E3-G.751
Mode
F-bits, M-bits (Frame)
X-bits (RAI)
P-bits (Parity)
7 Stuff Opportunity bits
C-bits (Justification Control)
Cb11 (AIC)
Cb13 (FEAC)
Cb3 (Path Parity)
Cb4 (FEBE)
Cb5 (DL)
Cb12, Cb2, Cb6-7
FAS (Frame)
A-bit (RAI)
N-bit (DL)
C
4 Stuff Opportunity bits
j-
bits (Justification Control)
Transmitter Overhead Bit Generation
(3)
(3)
(3)
(3)
Field
For the DS3 M13/M23, DS3 C-bit parity, E3-G.751, and E3-G.832 modes of
operation, the framer can use any of the following four techniques to insert framing
and Overhead bits:
!
!
!
!
The allocation of the Overhead bits to one method is done for groups of overheads.
The options vary for each one of the four main modes of operation. The Transmit
Overhead Insertion1 (i) control register and Transmit Overhead Insertion2 (i) control
register controls the allocation. The registers’ setting ability changes according to the
framer mode of operation.
Overhead bits in various modes.
(3)
(3)
Internal-Auto—Automatically generated by the internal circuitry, either because
the value is predetermined and constant (e.g., DS3 F- and M-bits), or as a response
to an incoming stimulus (e.g., automatic FEBE/REI).
Internal-Reg—The Overhead bits value to be transmitted and/or the control over
the value transmitted is performed through microprocessor-controlled registers.
External-Data—Overhead bits to be transmitted can be supplied with the data
stream.
External-Pin—The Overhead bit is input from an external pin (TEXT) based on
the gapped clock (TEXTCK) as set in the registers and controlled by the
microprocessor.
(2)
(2)
Mindspeed Technologies™
Internal-Auto
Table 2-1
indicates the availability for the various
Internal-Reg
Technique
External-Data
(1)
Functional Description
External-Pin
2
-
11