SPRUIM2H May 2020 – October 2023 AM2431 , AM2432 , AM2434 , AM6411 , AM6412 , AM6421 , AM6422 , AM6441 , AM6442
NOR flash architecture, introduced in 1988, is a flash technology. Unlike NAND, which is a sequential access device, NOR is directly addressable; that is, it is designed to be a random access device. NOR is best suited to devices used to store and run code or firmware, usually in small capacities. While NOR has fast read capabilities, it also has slow write and erase functions when compared to the NAND architecture.
Table 12-3251 summarizes the level of the NOR interface signals applied to external devices or memories.
Bus Operation | CLK | nADV | nCS | nOE | nWE | WAIT | DQ[15-0] |
---|---|---|---|---|---|---|---|
Read (asynchronous) | x | L | L | L | H | Asserted | Output |
Read (synchronous) | Running | L | L | L | H | Driven | Output |
Read (burst suspend) | Halted | x | L | H | H | Active | Output |
Write | x | L | L | H | L | Asserted | Input |
Output disable | x | x | L | H | H | Asserted | High-Z |
Standby | x | x | H | x | x | High-Z | High-Z |