STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

RM0008
Flexible static memory controller (FSMC)
19 Flexible static memory controller (FSMC)
Low-density devices are STM32F101xx, STM32F102xx and STM32F103xx
microcontrollers where the Flash memory density ranges between 16 and 32 Kbytes.
Medium-density devices are STM32F101xx and STM32F103xx microcontrollers where
the Flash memory density ranges between 32 and 128 Kbytes.
High-density devices are STM32F101xx and STM32F103xx microcontrollers where the
Flash memory density ranges between 256 and 512 Kbytes.
Connectivity line devices are STM32F105xx and STM32F107xx microcontrollers.
This section applies to high-density devices only.
19.1 FSMC main features
The FSMC block is able to interface with synchronous and asynchronous memories and 16-
bit PC memory cards. Its main purpose is to:
● Translate the AHB transactions into the appropriate external device protocol
● Meet the access timing requirements of the external devices
All external memories share the addresses, data and control signals with the controller.
Each external device is accessed by means of a unique chip select. The FSMC performs
only one access at a time to an external device.
The FSMC has the following main features:
● Interfaces with static memory-mapped devices including:
– Static random access memory (SRAM)
– Read-only memory (ROM)
– NOR Flash memory
– PSRAM (4 memory banks)
● Two banks of NAND Flash with ECC hardware that checks up to 8 Kbytes of data
● 16-bit PC Card compatible devices
● Supports burst mode access to synchronous devices (NOR Flash and PSRAM)
● 8- or 16-bit wide databus
● Independent chip select control for each memory bank
● Independent configuration for each memory bank
● Programmable timings to support a wide range of devices, in particular:
– Programmable wait states (up to 15)
– Programmable bus turnaround cycles (up to 15)
– Programmable output enable and write enable delays (up to 15)
– Independent read and write timings and protocol, so as to support the widest
variety of memories and timings
● Write enable and byte lane select outputs for use with PSRAM and SRAM devices
● Translation of 32-bit wide AHB transactions into consecutive 16-bit or 8-bit accesses to
external 16-bit or 8-bit devices
Doc ID 13902 Rev 9 409/995