What does the last suffix (the 18th digit) of Cypress Flash products denote in the manufacturer number on the label?
This final suffix in the manufacturer number is for internal Cypress use and has no meaning for the end customer.
Below is an example of the packaging label, with two numbers and a bar code.
OPN (Ordering Part Number): The first number is a 17-character ordering part number that is specified in the Cypress Datasheet, such as S29GL032N90BFI040
MFR# (Manufacturing Part Number): OPN + an additional character
The last suffix (18th) is only a code for Cypress internal tracking purpose. This last suffix has no bearing on the the form, fit, function, and operation of Flash, and has no impact on the options selected by the OPN.
Please note that when ordering Cypress products, this 18th suffix is not required. Although the MFR# may be found on associated documents, labels, and so forth, the MFR# is not stamped on the chip.