RFNAND Flash vs NOR Flash Memory: Key Differences
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This page compares NAND Flash vs NOR Flash Memory and mentions the key differences between NAND Flash and NOR Flash Memory architectures.
NAND Flash Memory Architecture
Image courtesy: Cypress Semiconductor Corporation (Now part of Infineon Technologies)
Figure 1 depicts the architecture of NAND flash memory. As shown, several memory cells (about eight) are connected in series. This arrangement resembles a NAND gate.
Advantages:
- Offers a much smaller cell size.
- Provides high write and erase speeds.
Disadvantages:
- Offers a slow read speed.
- Does not allow random access.
NOR Flash Memory Architecture
Image courtesy: Cypress Semiconductor Corporation (Now part of Infineon Technologies)
Figure 2 depicts the architecture of NOR flash memory. As shown, one end of the cell is interfaced to the source line and the other end to the bit line. This setup resembles a NOR gate.
Advantages:
- Offers enough address lines useful to map the complete memory range.
- Provides faster random read speeds.
Disadvantages:
- Offers a higher cost per bit.
- Provides slower write and erase speeds.
Difference between NAND Flash and NOR Flash Memory
The following table highlights the key differences between NAND Flash and NOR Flash memory types.
| Features | NAND Flash | NOR Flash |
|---|---|---|
| Capacity | Higher | Lower |
| Cost per bit | Lower | Higher |
| Random read speed | Slow | Fast |
| Write speed | Fast | Slow |
| Erase speed | Fast | Slow |
| Power on current | Lower | Higher |
| Standby current | Higher | Lower |
| Bit flipping | More common | Less common |
| Data retention | Low (~10 years) | Very high (~20 years for 1K program erase cycles) |
| Application | Data storage | Code storage and execution |
| Example | S34ML04G2 (Infineon) | S70GL02GT (Infineon) |
