FreeCalypso > hg > fc-usbser-tools
changeset 100:29bff463402e
doc/CP2102-EEPROM-format: part number byte confirmed
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Thu, 28 Sep 2023 05:39:44 +0000 |
| parents | c59011177e2e |
| children | ba741a1af0e3 |
| files | doc/CP2102-EEPROM-format |
| diffstat | 1 files changed, 10 insertions(+), 3 deletions(-) [+] |
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--- a/doc/CP2102-EEPROM-format Thu Sep 28 05:25:39 2023 +0000 +++ b/doc/CP2102-EEPROM-format Thu Sep 28 05:39:44 2023 +0000 @@ -14,6 +14,13 @@ fixed area allocated for it, no pointer-to-string scheme like in FTDI's EEPROMs; +* Unlike FTDI EEPROMs, CP2102 EEPROM is most certainly NOT optional - a blank + or garbage-filled EEPROM will result in a non-functional chip; + +* There is no checksum - because there is nothing for the chip to "fall back" + on when the EEPROM is bad, there is no point in checking the EEPROM content + for validity; + * The logical structure of CP2102 EEPROM is byte-oriented - no 16-bit words as elementary units. @@ -72,9 +79,9 @@ Address 0x37FF, 1 byte: - Python cp210x package notes indicate that this byte holds the part - number, presumably the one returned by the vendor-specific command that - retrieves it. This aspect remains to be tested at FreeCalypso HQ. + Part number code 0x02 for CP2102. The chip returns this EEPROM byte + when queried (via CP210x family-specific command) for its part number, + as in cp2102-read-partno. Address 0x3800, 4 bytes: