16.1 Error Checking in the Processor

SECDED ECC Matrices for Data and Tag Buses

The data bits in Figure 16-1 correspond to SysAD(63:0), SCData(127:64), or SCData(63:0). The check bits in Figure 16-1 correspond to SysADC(7:0), SCDChk(15:8), or SCDChk(7:0).

The check bits in Figure 16-4, shown later in this chapter, correspond to SCTChk(6:0) and the data bits in Figure 16-4 correspond to SCTag(24:0).

The parity check matrices shown in these two figures generate the ECC code for a fixed-width data word; they can also locate the data bit in error. In Figure 16-1, the data word length is 64 bits; in Figure 16-4, the data word length is 25 bits.

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