flash
Nand Flash
- Raspberry Pi CM Module 4 - RMP-RPI-CM4-dat
Nor Flash
What is NOR Flash?
NOR flash is a type of non-volatile memory that allows random read access. It is commonly used for storing firmware and allows executing code directly from flash (XIP - Execute In Place).
Comparison Table
| Feature | Parallel NOR Flash | SPI NOR Flash (SPI Flash) |
|---|---|---|
| Interface | Parallel (8/16-bit bus) | Serial (SPI: MOSI, MISO, SCLK) |
| Speed | High (fast random access) | Lower (due to serial nature) |
| Pins Required | Many (20+ pins) | Few (4–6 pins) |
| Physical Size | Larger | Smaller |
| Cost | More expensive | Cheaper |
| Power Consumption | Higher | Lower |
| Read Access | Random access (byte-wise) | Page-based, sequential access |
| Write Access | Sector/page erase/write | Sector/page erase/write |
| XIP Support | Yes (native) | Limited or requires mapping |
| Use Cases | Boot code, firmware (MCUs, routers) | Microcontrollers, IoT, sensors |
| Typical Capacity | Up to 512 MB | Up to 2 GB |
Summary
- SPI Flash is a type of NOR Flash that uses a serial interface (SPI).
- SPI NOR Flash sacrifices speed and flexibility for lower cost, lower pin count, and small size.
- Parallel NOR Flash is better for code execution and high-speed access.
S29GL128P90TFIR10 - NOR Flash 128Mb 3V 90ns Parallel NOR Flash
SCH
- flash with bypass button
SPI NAND
SPI Nor VS. NAND Flash
✅ Summary Table
| Feature | SPI NOR | SPI NAND |
|---|---|---|
| Capacity | Low to medium | Medium to very high |
| Random read speed | ✅ Fast | ❌ Slower |
| Write/erase speed | ❌ Slower | ✅ Faster |
| Reliability | ✅ High | ❌ Needs ECC |
| Bootable (XIP) | ✅ Yes | ❌ No |
| Cost per bit | ❌ Higher | ✅ Lower |
TL;DR
- 🧠 SPI NOR Flash = small, reliable, fast reads → great for firmware.
- 📦 SPI NAND Flash = large, cheaper, needs ECC → great for data storage.
📦 Common Winbond SPI NOR Flash Models
Winbond's SPI NOR flash chips are usually labeled W25Q or W25X series.
They vary by capacity, voltage, speed, and features like Dual/Quad SPI.
🧰 Common W25Q Series (Most Popular)
| Model | Capacity | Voltage | Features |
|---|---|---|---|
| W25Q16JV | 16 Mbit | 2.7–3.6V | Standard SPI, Dual/Quad SPI |
| W25Q32JV | 32 Mbit | 2.7–3.6V | Very popular, common in MCUs |
| W25Q64JV | 64 Mbit | 2.7–3.6V | Standard/Dual/Quad SPI |
| W25Q128JV | 128 Mbit | 2.7–3.6V | XIP, dual/quad SPI support |
| W25Q256JV | 256 Mbit | 2.7–3.6V | Larger firmware/data storage |
un-sort
TC58FVM7(T/B)2AFT(65/80) - 128-MBIT (16M × 8 BITS / 8M × 16 BITS) CMOS FLASH MEMORY
AM29LV116DT-90EI - IC FLASH 16MBIT PARALLEL 40TSOP
spansion - S29GL-P MirrorBit® Flash Family - S29GL01GP, S29GL512P, S29GL256P, S29GL128P 1 Gigabit, 512 Megabit, 256 Megabit and 128 Megabit 3.0 Volt-only Page Mode Flash Memory featuring 90 nm MirrorBit Process Technology
IC FLASH 32MBIT PARALLEL 48TSOP - SST39VF3202-70-4I-EKE - FLASH Memory IC 32Mbit Parallel 70 ns 48-TSOP
S29GL01GS, S29GL512S, S29GL256S, S29GL128S - 128 Mb/256 Mb/512 Mb/1 Gb GL-S MIRRORBIT™ flash Parallel, 3.0 V