
XRT94L33
xr
Rev.1.2.0.
3-CHANNEL DS3/E3/STS-1 TO STS-3/STM-1 MAPPER IC DATA SHEET
328
2.2.9.5.12
SUPPORT/HANDLING OF THE M1 BYTE
2.2.9.5.13
SUPPORT/HANDLING OF THE E2 BYTE
The Transmit STS-3 TOH Processor block permits the user to control the value of the E2 byte, which is to be
transmitted via the “outbound” STS-3 data-stream, by either or the following options.
Setting and controlling the E2 byte via software
Setting and controlling the E2 byte via the “TxPOH Input Port”
The details and instructions for using either of these features are presented below.
2.2.9.5.13.1
Setting and Controlling the outbound E2 byte via Software
The Transmit STS-3 TOH Processor block permits the user to specify the contents of the E2 byte within the
outbound STS-3 data-stream via software command.
The user can configure the Transmit STS-3 TOH Processor block to accomplish this by performing the
following steps.
STEP 1 – Write the value “1” into Bit 5 (E2 Insert Method) within the “Transmit STS-3 Transport –
SONET Transmit Control Register – Byte 1, as depicted below.
Transmit STS-3Transport – SONET Transmit Control Register – Byte 1 (Address = 0x1902)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Reserved
E2 Insert
Method
E1 Insert
Method
F1 Insert
Method
S1 Insert
Method
K1K2 Insert
Method
M0M1 Insert
Method[1]
R/O
R/W
0
1
X
The step configures the Transmit STS-3 TOH Processor block to read out the contents of the “Transmit STS-
3 Transport – E2 Byte Value Register, and load this value into the E2 byte position within each outbound
STS-3 data-stream.
STEP 2 – Write the desired byte values (for the outbound E2 byte) into the “Transmit STS-3 Transport
– E2 Byte Value Register.
The bit-format for this register is presented below.
Transmit STS-3 Transport – Transmit E2 Byte Value Register (Address = 0x1947)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Transmit_E2_Byte_Value[7:0]
R/W
0
2.2.9.5.13.2
Setting and Controlling the outbound E2 byte via “TxPOH Input Port”
The Transmit STS-3 TOH Processor block permits the user to specify the contents of the E2 bytes within the
“outbound” STS-3 data-stream via the data applied to the “TxPOH_n” input port.
The user can configure the Transmit STS-3 TOH Processor block to accomplish this by performing the
following steps.
STEP 1 – Write the value “1” into Bit 4 (STS-3 TOH Insert) within the “Mapper Control Register – Byte
2”, as depicted below.