tdat04622 ETC-unknow, tdat04622 Datasheet - Page 16

• Manufacturer Part Number: tdat04622
• Description: Tdat Sonet/sdh 155/622/2488 Mbits/s Data Interfaces
• Manufacturer: ETC-unknow

TDAT042G5 Device Advisory
Advisory
for Version 1 and 1A of the Device
May 2001
UTOPIA (UT)
(continued)
UT4. FIFO Overflow and Error Reporting
If the RxFIFO overflows, RxEOP is not asserted as expected. Therefore, when errors occur, two packets will be
corrupted instead of one because two start of packets (SOPs) occurred without an end of packet (EOP). RxERR is
not asserted when the above overflow condition occurs. No effect is noticeable in the ATM mode. Channel A works
as expected; this problem occurs in channels B, C, and D.
Workaround
This error is detectable in the status registers. No workaround is available for this condition.
Corrective Action
This condition will be addressed in future versions of the device.
UT5. Timing Difference Between Direct and Polled Status Modes
In the receive direction of the MPHY mode, RxPA[A] shows the polled packet (or ATM) available status for all four
slices, while the RxPA[B], RxPA[C], and RxPA[D] show the direct status states of their respective FIFOs. In some
cases, the status of RxPA[A] does not agree with the status of RxPA[D:B]. The direct status indication has one
additional cycle of pipeline delay from that of the polled status.
Workaround
This is informational only. No workaround is available for this condition.
Corrective Action
No corrective action is required for this condition.
UT6. UTOPIA Interface D Nonfunctional in Some Mixed MPHY and Point-to-Point
Configurations
When TDAT042G5 is configured with slice D in a point-to-point mode, slice D is nonfunctional in one special case.
If UTOPIA interfaces A and B are configured for 32-bit MPHY operation with slice C as part of the polled channels,
interface D will be nonfunctional and cannot be independently configured in a UTOPIA Level 2 point-to-point mode.
This condition does not occur in 16-bit MPHY operation.
Workaround
For mixed MPHY and point-to-point configuration, use UTOPIA slice D for MPHY mode instead of slice C.
UTOPIA slice C will then be available for normal point-to point mode.
Corrective Action
This condition will be addressed in future versions of the device.
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Agere Systems Inc.