28953-SWG-001-A Datasheet, PDF (69/183 Pages) M/A-COM Technology Solutions, Inc. – Application and Channel Unit Software

RS8953B
Application and Channel Unit Software Developer’s Guide
6.0 Channel Unit Code
6.1 Configurations
6.1.5 CU_1E1
The CU_1E1 runs the standard one-loop E1 mapping at 2320 kbps with one loop carrying all the E1
payload. Each payload block contains one Z-bit followed by 36 payload bytes (Figure 6-6). The
relation between the payload bytes and PCM time slot is listed in Table 6-6.
Figure 6-6. Payload Block Structure for 1E1 Application
CH1
Zn BYTE1 BYTE2 BYTE3
...
BYTE36
Table 6-6. 1E1 Framing
Byte 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Time slot 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Byte 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Time slot 18 19 20 21 22 23 24 25 26 27 28 29 30 31 * * * *
NOTE(S): * = DBANK
6.1.6 Modifying the Code for Custom Applications (_CU_CUSTOM)
To customize the channel unit code for applications other than standard 1T1, 2T1, 1E1, 2E1, and
3E1, the following parts of the channel unit code must be modified.
6.1.6.1 Rate_values[][]
The rate_values[][] array is a matrix of register values for the various rate configurations, i.e., 1T1,
2T1, 1E1, 2E1, 3E1, and _CU_CUSTOM. The rate_values[][] array is defined in CU_INIT.C. Only
registers that require different programming values between the various configurations are included
in this matrix. Other registers that are programmed to the same value between various
configurations are hard coded into the various initialization functions. The first dimension of the
array indexes the rate, and the second dimension indexes the channel unit register. See
CU_TABLE.H for the list of registers. The channel unit initialization functions index this array to
determine the desired register value for the current configuration.
6.1.6.2 CU_MAP.C
Three functions in the CU_MAP.C file initialize the transmit routing table (see Section 10.9),
receive combination table (see Section 10.10), transmit payload map registers (see Section 10.11)
and receive payload map registers (see Section 10.12) based on the channel unit configuration.
• _CuInitMapper()
• _CuInitRouteTable()
• _CuInitCombineTable()
The customer must modify the portions of the code in the above functions that are surrounded
by CU_CUSTOM compiler flag.
100418C
Conexant
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