ST STM32F412 User Manual

RM0402 Rev 6 281/1163
RM0402 Flexible static memory controller (FSMC)
287
SRAM/NOR-Flash chip-select timing register for bank x (FSMC_BTRx)
Address offset: 0x04 + 8 * (x – 1), (x = 1 to 4)
Reset value: 0x0FFF FFFF
This register contains the control information of each memory bank, used for SRAMs,
PSRAM and NOR Flash memories.If the EXTMOD bit is set in the FSMC_BCRx register,
then this register is partitioned for write and read access, that is, 2 registers are available:
Bit 9 WAITPOL: Wait signal polarity bit
Defines the polarity of the wait signal from memory used for either in Synchronous or Asynchronous
mode.
0: NWAIT active low (default after reset)
1: NWAIT active high
Bit 8 BURSTEN: Burst enable bit
This bit enables/disables synchronous accesses during read operations. It is valid only for
synchronous memories operating in Burst mode.
0: Burst mode disabled (default after reset). Read accesses are performed in Asynchronous mode.
1: Burst mode enable. Read accesses are performed in Synchronous mode.
Bit 7 Reserved, must be kept at reset value.
Bit 6 FACCEN: Flash access enable
Enables NOR Flash memory access operations.
0: Corresponding NOR Flash memory access is disabled.
1: Corresponding NOR Flash memory access is enabled (default after reset).
Bits 5:4 MWID[1:0]: Memory data bus width
Defines the external memory device width, valid for all type of memories.
00: 8 bits
01: 16 bits (default after reset)
10: reserved
11: reserved
Bits 3:2 MTYP[1:0]: Memory type
Defines the type of external memory attached to the corresponding memory bank.
00: SRAM (default after reset for Bank 2...4)
01: PSRAM (CRAM)
10: NOR Flash/OneNAND Flash (default after reset for Bank 1)
11: reserved
Bit 1 MUXEN: Address/data multiplexing enable bit
When this bit is set, the address and data values are multiplexed on the data bus, valid only with
NOR and PSRAM memories:
0: Address/data non multiplexed
1: Address/data multiplexed on databus (default after reset)
Bit 0 MBKEN: Memory bank enable bit
Enables the memory bank. After reset Bank1 is enabled, all others are disabled. Accessing a
disabled bank causes an ERROR on AHB bus.
0: Corresponding memory bank is disabled.
1: Corresponding memory bank is enabled.

ST STM32F412 Specifications

General

Brand	ST
Model	STM32F412
Category	Microcontrollers
Language	English