Elm_Location_Status_I Value Decoding Table - Texas Instruments TMS320C6A816 Series Technical Reference Manual

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1.15.3.5 Processing Sequence
While the error-location engine is busy processing one syndrome polynomial, further syndrome
polynomials can be written. They are processed when the current processing completes.
The engine completes early when:
• No error is detected; that is, when the ELM_LOCATION_STATUS_i[8] ECC_CORRECTABLE bit is set
to 1 and the ELM_LOCATION_STATUS_i[4:0] ECC_NB_ERRORS bit field is set to 0x0.
• Too many errors are detected; that is, when the ELM_LOCATION_STATUS_i[8]
ECC_CORRECTABLE bit is set to 0 while the ELM_LOCATION_STATUS_i[4:0] ECC_NB_ERRORS
bit field is set with the value output by the error-location engine. The reported number of errors is not
ensured if ECC_CORRECTABLE is 0.
If the engine completes early, the associated error-location registers ELM_ERROR_LOCATION_0_i to
ELM_ERROR_LOCATION_15_i are not updated (i = 0 to 7).
In all other cases, the engine goes through the entire error-location process. Each time an error-location is
found, it is logged in the associated ECC_ERROR_LOCATION bit field. The first error detected is logged
in the ELM_ERROR_LOCATION_0_i[12:0] ECC_ERROR_LOCATION bit field; the second in the
ELM_ERROR_LOCATION_1_i[12:0] ECC_ERROR_LOCATION bit field, and so on.
Table 1-127. ELM_LOCATION_STATUS_i Value Decoding Table
ECC_CORRECT ECC_NB_ERRORS
ABLE Value Value
1 0
1 ≠ 0
0 Any
1.15.3.6 Processing Completion
When the processing for a given syndrome polynomial completes, its
ELM_SYNDROME_FRAGMENT_6_i[16] SYNDROME_VALID bit is reset. It must not be set again until
the exit status registers, ELM_LOCATION_STATUS_i (i = 0 to 7), for this processing are checked. Failure
to comply with this rule leads to potential loss of the first polynomial process data output.
The error-location engine signals the process completion to the ELM. When this event is detected, the
corresponding ELM_IRQSTATUS[i] LOC_VALID_i bit is set (i = 0 to 7). The processing-exit status is
available from the associated ELM_LOCATION_STATUS_i register, and error locations are stored in order
in the ECC_ERROR_LOCATION fields. The software must only read valid error-location registers based
on the number of errors detected and located.
Immediately after the error-location engine completes, a new syndrome polynomial can be processed, if
any is available, as reported by the ELM_SYNDROME_FRAGMENT_6_i[16] SYNDROME_VALID validity
bit, depending on the configured error-correction level. If several syndrome polynomials are available, a
round-robin arbitration is used to select one for processing.
In continuous mode (that is, all bits in ELM_PAGE_CTRL are reset), an interrupt is triggered whenever a
ELM_IRQSTATUS[i] LOC_VALID_i bit is asserted. The CPU must read the ELM_IRQSTATUS register to
determine which polynomial is processed and retrieve the exit status and error locations
(ELM_LOCATION_STATUS_i and ELM_ERROR_LOCATION_0_i to ELM_ERROR_LOCATION_15_i).
When done, the CPU must clear the corresponding ELM_IRQSTATUS[i] LOC_VALID_i bit by writing it to
1. Other status bits must be written to 0 so that other interrupts are not unintentionally cleared. When
using this mode, the ELM_IRQSTATUS[8] PAGE_VALID interrupt is never triggered.
SPRUGX9 – 15 April 2011
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Preliminary
Status Number of Errors
Detected
OK 0
OK ECC_NB_ERRORS Correct the data buffer read based on the
Failed Unknown
© 2011, Texas Instruments Incorporated
Action Required
None
ELM_ERROR_LOCATION_0_i to
ELM_ERROR_LOCATION_15_i results.
Software-dependant
Chip Level Resources
Error Location Module
251