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P89LPC9408 -XDATA memory

Syed Moulana

In P89LPC9408.pdf (Product Data Sheet)
Type Data RAM Size (bytes)
DATA 128
IDATA 256
XDATA 512
Total 768 bytes

is the XDATA refers to on-chip EEPROM 512 BYTES?

Thanks

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  • 0

    The way I read the data sheet, the EEPROM is not xdata. See Figure 2, which shows both a 512-byte "auxiliary RAM" and a 512-byte EEPROM block. Also, the sentence I emphasize below implies that you do not read the EEPROM as part of xdata, but rather through SFR operations. The programming manual for this part will no doubt have the details.

    7.28 Data EEPROM
    The P89LPC9408 has 512bytes of on-chip Data EEPROM. The Data EEPROM is SFR based, byte readable, byte writable,and erasable (via row fill and sector fill). The user can read, write and fill the memory via SFRs and one interrupt. This Data EEPROM provides 100,000 minimum erase/program cycles for each byte.

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  • 0

    The way I read the data sheet, the EEPROM is not xdata. See Figure 2, which shows both a 512-byte "auxiliary RAM" and a 512-byte EEPROM block. Also, the sentence I emphasize below implies that you do not read the EEPROM as part of xdata, but rather through SFR operations. The programming manual for this part will no doubt have the details.

    7.28 Data EEPROM
    The P89LPC9408 has 512bytes of on-chip Data EEPROM. The Data EEPROM is SFR based, byte readable, byte writable,and erasable (via row fill and sector fill). The user can read, write and fill the memory via SFRs and one interrupt. This Data EEPROM provides 100,000 minimum erase/program cycles for each byte.

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