Specifications

116 Product Errata
41322 Rev. 3.84 August 2011
Revision Guide for AMD Family 10h Processors
398 HyperTransport™ Links In Retry Mode May Experience High Bit
Error Rate At Specific Link and Northbridge Clock Frequencies
Description
The processor HyperTransport™ link transmit FIFOs may underflow, resulting in bit errors. This
erratum only applies when all of the following conditions are satisfied:
• Links are in retry mode.
• The HyperTransport link clock frequency is greater than the northbridge clock frequency.
• The HyperTransport link clock frequency is an odd multiple of 200 MHz.
• LDTSTOP# has not been asserted since the last warm reset.
Potential Effect on System
The link may fail to train due to multiple bit errors, or experience excessive retries. This behavior
may be intermittent.
Suggested Workaround
At link and northbridge frequency settings where the erratum applies, system software should
subtract 0010b from the four bit value programmed into Link FIFO Read Pointer Optimization
Registers F4x1[9C, 94, 8C, 84]_x[DF, CF][7:4] (XmtRdPtr). If the result of the subtraction is
negative, truncate it to four bits of precision.
Fix Planned
Yes