DS33R41 Maxim Integrated Products, DS33R41 Datasheet - Page 110

• Manufacturer Part Number: DS33R41
• Description: Network Controller & Processor ICs Inverse-Multiplexing Ethernet Mapper wit
• Manufacturer: Maxim Integrated Products

10.26 Payload Error-Insertion Function (T1 Mode Only)
An error-insertion function is available in the transceiver and is used to create errors in the payload portion of the
T1 frame in the transmit path. This function is only available in T1 mode. Errors can be inserted over the entire
frame or the user can select which channels are to be corrupted. Errors are created by inverting the last bit in the
count sequence. For example, if the error rate 1 in 16 is selected, the 16th bit is inverted. F-bits are excluded from
the count and are never corrupted. Error rate changes occur on frame boundaries. Error-insertion options include
continuous and absolute number with both options supporting selectable insertion rates.
Table 10-14. Transmit Error-Insertion Setup Sequence
10.26.1 Number-of-Errors Registers
The number-of-error registers determine how many errors are generated. Up to 1023 errors can be generated. The
host loads the number of errors to be generated into the TR.NOE1 and TR.NOE2 registers. The host can also
update the number of errors to be created by first loading the prescribed value into the TR.NOE registers and then
toggling the WNOE bit in the error-rate control registers.
Table 10-15 Error Insertion Examples
10.26.2 Number of Errors Left Register
The host can read the NOELx registers at any time to determine how many errors are left to be inserted.
STEP
2A
2B
or
1
VALUE
3FFh
000h
001h
002h
Enter desired error rate in the TR.ERC register. Note: If TR.ER3 through TR.ER0 = 0,
no errors are generated even if the constant error-insertion feature is enabled.
For constant error insertion, set CE = 1 (TR.ERC.4).
For a defined number of errors:
–
–
–
Set CE = 0 (TR.ERC.4)
Load TR.NOE1 and TR.NOE2 with the number of errors to be inserted
Toggle WNOE (TR.ERC.7) from 0 to 1 to begin error insertion
Do not create any errors
Create a single error
Create two errors
Create 1023 errors
WRITE
No errors left to be inserted
One error left to be inserted
Two errors left to be inserted
1023 errors left to be inserted
ACTION
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