SLASFM1A June 2025 – December 2025 AFE10004-EP
PRODUCTION DATA
Before completing the EEPROM load sequence, a CRC error-check is performed by the device. The CRC polynomial is x12 + x11 + x3 + x2 + x + 1. The CRC check result is reported through the EECRC bit. If a CRC error is detected, the operating memory values are compromised; reset the device or burn the EEPROM again for proper operation.
For added robustness, a single error correction and double error detection (SECDED) circuit based on the Hamming code is added to data in the LUT pages (Page 4 and Page 5). The SECDED circuit uses four Hamming code bits and a parity bit. The interleaved Hamming and LUT data are stored in EEPROM, and Table 6-10 shows these bits.
| DATA AND BIT POSITION | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Data and Hamming code bits in operating memory | P | H3 | H2 | H1 | H0 | X | X | X | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 | |||||||
| Data and Hamming code interleaved bits | X | X | X | D7 | D6 | D5 | D4 | H3 | D3 | D2 | D1 | H2 | D0 | H1 | H0 | P | |||||||
The SECDED circuit checks the data integrity on every LUT register access. The parity bit (P) and four Hamming code bits (H[3:0]) in the HAMM registers equal all zeros if no error is present in the associated LUT data register. If P = 1 then a single error has been detected and corrected. The value in the H[3:0] bits represents the position of the bit error with respect to the interleaved bits. For example, if P = 1 and H[3:0] = 0x5, an error is detected and corrected in D1.
If P = 0 and H[3:0] ≠ 0, then a double error has been detected. No correction is done in this case.
Table 6-11 summarizes the device EEPROM integrity checks.
| STATUS BIT NAME | DESCRIPTION |
|---|---|
| EECRC | 0 = No CRC error detected. 1 = A CRC error is detected during a EEPROM load. The operating memory data are compromised. |
| EERDY | 0 = The EEPROM burn is in progress. 1 = The EEPROM burn is complete. |
| DED | 0 = No double-bit error detected. 1 = A double-bit error is detected when accessing a LUT register in the operating memory. The error is not corrected. |
| SED | 0 = No single-bit error detected. 1 = A single-bit error is detected when accessing a LUT register in the operating memory. The error is corrected. |