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diff --git a/docs/source/libmaple/api/fsmc.rst b/docs/source/libmaple/api/fsmc.rst new file mode 100644 index 0000000..e2bf87a --- /dev/null +++ b/docs/source/libmaple/api/fsmc.rst @@ -0,0 +1,235 @@ +.. highlight:: c +.. _libmaple-fsmc: + +``<libmaple/fsmc.h>`` +===================== + +Flexible Static Memory Controller (FSMC) support. The FSMC peripheral +is only available on some targets. Including this header on a target +without an FSMC will cause a compilation error. Check your target's +documentation to determine if it's available. You can also use +:ref:`STM32_HAVE_FSMC <libmaple-stm32-STM32_HAVE_FSMC>` from +``<libmaple/stm32.h>`` to determine whether your target has an FSMC at +build time. + +All functionality documented here is portable. + +.. contents:: Contents + :local: + +Usage Note +---------- + +FSMC support is fairly limited at this time. Current Leaflabs boards +only use the FSMC to interface with external SRAM chips, so that's +what there's the most support for (:ref:`patches welcome! +<libmaple-contributing>`). Even for use with SRAM, you will still need +to program some registers directly. + +To use the FSMC with an SRAM chip, first call +:ref:`fsmc_sram_init_gpios() <libmaple-fsmc-fsmc_sram_init_gpios>` to +configure its data, address, and control lines. Then, turn on the +FSMC clock (by calling :ref:`rcc_clk_enable(RCC_FSMC) +<libmaple-rcc-rcc_clk_enable>`). You can then configure the relevant +:ref:`fsmc_nor_psram_reg_map <libmaple-fsmc-fsmc_nor_psram_reg_map>` +``BCR`` register yourself for the SRAM chip you are using. + +You can additionally use :ref:`fsmc_nor_psram_set_datast() +<libmaple-fsmc-fsmc_nor_psram_set_datast>` and +:ref:`fsmc_nor_psram_set_datast() <libmaple-fsmc-fsmc_nor_psram_set_datast>` +to control read/write timing. + +Devices +------- + +None at this time. + +Functions +--------- + +.. _libmaple-fsmc-fsmc_sram_init_gpios: +.. doxygenfunction:: fsmc_sram_init_gpios +.. _libmaple-fsmc-fsmc_nor_psram_set_datast: +.. doxygenfunction:: fsmc_nor_psram_set_datast +.. _libmaple-fsmc-fsmc_nor_psram_set_addset: +.. doxygenfunction:: fsmc_nor_psram_set_addset + +Register Maps +------------- + +The general purpose register map type is ``fsmc_reg_map``; its base +pointer is ``FSMC_BASE``. The ``fsmc_nor_psram_reg_map`` type is for +use configuring the registers for an individual NOR/PSRAM region +(``FSMC_BCRx``, ``FSMC_BTRx``, and ``FSMC_BWTRx``); the relevant base +pointers are ``FSMC_NOR_PSRAM_REGION1`` through +``FSMC_NOR_PSRAM_REGION4``. + +.. doxygendefine:: FSMC_BASE + +.. doxygendefine:: FSMC_NOR_PSRAM1_BASE +.. doxygendefine:: FSMC_NOR_PSRAM2_BASE +.. doxygendefine:: FSMC_NOR_PSRAM3_BASE +.. doxygendefine:: FSMC_NOR_PSRAM4_BASE + +.. doxygenstruct:: fsmc_reg_map +.. _libmaple-fsmc-fsmc_nor_psram_reg_map: +.. doxygenstruct:: fsmc_nor_psram_reg_map + +Memory Bank Boundary Addresses +------------------------------ + +Reading and writing data on an external memory chip using FSMC is done +by reading and writing from addresses in special memory-mapped +sections of the address space called *memory banks*. + +This is convenient, since it implies that the usual load and store +instructions used for I/O with the internal SRAM are also used to +perform bus transactions with the external memory chip. (Which means +you can use ``memcpy()`` etc. on external memory.) + +Pointers to the memory banks' base addresses are given by the +following macros. + +.. doxygendefine:: FSMC_BANK1 +.. doxygendefine:: FSMC_BANK2 +.. doxygendefine:: FSMC_BANK3 +.. doxygendefine:: FSMC_BANK4 + +.. doxygendefine:: FSMC_NOR_PSRAM_REGION1 +.. doxygendefine:: FSMC_NOR_PSRAM_REGION2 +.. doxygendefine:: FSMC_NOR_PSRAM_REGION3 +.. doxygendefine:: FSMC_NOR_PSRAM_REGION4 + +Register Bit Definitions +------------------------ + +These are given as source code. + +:: + + /* NOR/PSRAM chip-select control registers */ + + #define FSMC_BCR_CBURSTRW_BIT 19 + #define FSMC_BCR_ASYNCWAIT_BIT 15 + #define FSMC_BCR_EXTMOD_BIT 14 + #define FSMC_BCR_WAITEN_BIT 13 + #define FSMC_BCR_WREN_BIT 12 + #define FSMC_BCR_WAITCFG_BIT 11 + #define FSMC_BCR_WRAPMOD_BIT 10 + #define FSMC_BCR_WAITPOL_BIT 9 + #define FSMC_BCR_BURSTEN_BIT 8 + #define FSMC_BCR_FACCEN_BIT 6 + #define FSMC_BCR_MUXEN_BIT 1 + #define FSMC_BCR_MBKEN_BIT 0 + + #define FSMC_BCR_CBURSTRW (1U << FSMC_BCR_CBURSTRW_BIT) + #define FSMC_BCR_ASYNCWAIT (1U << FSMC_BCR_ASYNCWAIT_BIT) + #define FSMC_BCR_EXTMOD (1U << FSMC_BCR_EXTMOD_BIT) + #define FSMC_BCR_WAITEN (1U << FSMC_BCR_WAITEN_BIT) + #define FSMC_BCR_WREN (1U << FSMC_BCR_WREN_BIT) + #define FSMC_BCR_WAITCFG (1U << FSMC_BCR_WAITCFG_BIT) + #define FSMC_BCR_WRAPMOD (1U << FSMC_BCR_WRAPMOD_BIT) + #define FSMC_BCR_WAITPOL (1U << FSMC_BCR_WAITPOL_BIT) + #define FSMC_BCR_BURSTEN (1U << FSMC_BCR_BURSTEN_BIT) + #define FSMC_BCR_FACCEN (1U << FSMC_BCR_FACCEN_BIT) + #define FSMC_BCR_MWID (0x3 << 4) + #define FSMC_BCR_MWID_8BITS (0x0 << 4) + #define FSMC_BCR_MWID_16BITS (0x1 << 4) + #define FSMC_BCR_MTYP (0x3 << 2) + #define FSMC_BCR_MTYP_SRAM (0x0 << 2) + #define FSMC_BCR_MTYP_PSRAM (0x1 << 2) + #define FSMC_BCR_MTYP_NOR_FLASH (0x2 << 2) + #define FSMC_BCR_MUXEN (1U << FSMC_BCR_MUXEN_BIT) + #define FSMC_BCR_MBKEN (1U << FSMC_BCR_MBKEN_BIT) + + /* SRAM/NOR-Flash chip-select timing registers */ + + #define FSMC_BTR_ACCMOD (0x3 << 28) + #define FSMC_BTR_ACCMOD_A (0x0 << 28) + #define FSMC_BTR_ACCMOD_B (0x1 << 28) + #define FSMC_BTR_ACCMOD_C (0x2 << 28) + #define FSMC_BTR_ACCMOD_D (0x3 << 28) + #define FSMC_BTR_DATLAT (0xF << 24) + #define FSMC_BTR_CLKDIV (0xF << 20) + #define FSMC_BTR_BUSTURN (0xF << 16) + #define FSMC_BTR_DATAST (0xFF << 8) + #define FSMC_BTR_ADDHLD (0xF << 4) + #define FSMC_BTR_ADDSET 0xF + + /* SRAM/NOR-Flash write timing registers */ + + #define FSMC_BWTR_ACCMOD (0x3 << 28) + #define FSMC_BWTR_ACCMOD_A (0x0 << 28) + #define FSMC_BWTR_ACCMOD_B (0x1 << 28) + #define FSMC_BWTR_ACCMOD_C (0x2 << 28) + #define FSMC_BWTR_ACCMOD_D (0x3 << 28) + #define FSMC_BWTR_DATLAT (0xF << 24) + #define FSMC_BWTR_CLKDIV (0xF << 20) + #define FSMC_BWTR_DATAST (0xFF << 8) + #define FSMC_BWTR_ADDHLD (0xF << 4) + #define FSMC_BWTR_ADDSET 0xF + + /* NAND Flash/PC Card controller registers */ + + #define FSMC_PCR_ECCEN_BIT 6 + #define FSMC_PCR_PTYP_BIT 3 + #define FSMC_PCR_PBKEN_BIT 2 + #define FSMC_PCR_PWAITEN_BIT 1 + + #define FSMC_PCR_ECCPS (0x7 << 17) + #define FSMC_PCR_ECCPS_256B (0x0 << 17) + #define FSMC_PCR_ECCPS_512B (0x1 << 17) + #define FSMC_PCR_ECCPS_1024B (0x2 << 17) + #define FSMC_PCR_ECCPS_2048B (0x3 << 17) + #define FSMC_PCR_ECCPS_4096B (0x4 << 17) + #define FSMC_PCR_ECCPS_8192B (0x5 << 17) + #define FSMC_PCR_TAR (0xF << 13) + #define FSMC_PCR_TCLR (0xF << 9) + #define FSMC_PCR_ECCEN (1U << FSMC_PCR_ECCEN_BIT) + #define FSMC_PCR_PWID (0x3 << 4) + #define FSMC_PCR_PWID_8BITS (0x0 << 4) + #define FSMC_PCR_PWID_16BITS (0x1 << 4) + #define FSMC_PCR_PTYP (1U << FSMC_PCR_PTYP_BIT) + #define FSMC_PCR_PTYP_PC_CF_PCMCIA (0x0 << FSMC_PCR_PTYP_BIT) + #define FSMC_PCR_PTYP_NAND (0x1 << FSMC_PCR_PTYP_BIT) + #define FSMC_PCR_PBKEN (1U << FSMC_PCR_PBKEN_BIT) + #define FSMC_PCR_PWAITEN (1U << FSMC_PCR_PWAITEN_BIT) + + /* FIFO status and interrupt registers */ + + #define FSMC_SR_FEMPT_BIT 6 + #define FSMC_SR_IFEN_BIT 5 + #define FSMC_SR_ILEN_BIT 4 + #define FSMC_SR_IREN_BIT 3 + #define FSMC_SR_IFS_BIT 2 + #define FSMC_SR_ILS_BIT 1 + #define FSMC_SR_IRS_BIT 0 + + #define FSMC_SR_FEMPT (1U << FSMC_SR_FEMPT_BIT) + #define FSMC_SR_IFEN (1U << FSMC_SR_IFEN_BIT) + #define FSMC_SR_ILEN (1U << FSMC_SR_ILEN_BIT) + #define FSMC_SR_IREN (1U << FSMC_SR_IREN_BIT) + #define FSMC_SR_IFS (1U << FSMC_SR_IFS_BIT) + #define FSMC_SR_ILS (1U << FSMC_SR_ILS_BIT) + #define FSMC_SR_IRS (1U << FSMC_SR_IRS_BIT) + + /* Common memory space timing registers */ + + #define FSMC_PMEM_MEMHIZ (0xFF << 24) + #define FSMC_PMEM_MEMHOLD (0xFF << 16) + #define FSMC_PMEM_MEMWAIT (0xFF << 8) + #define FSMC_PMEM_MEMSET 0xFF + + /* Attribute memory space timing registers */ + + #define FSMC_PATT_ATTHIZ (0xFF << 24) + #define FSMC_PATT_ATTHOLD (0xFF << 16) + #define FSMC_PATT_ATTWAIT (0xFF << 8) + #define FSMC_PATT_ATTSET 0xFF + + /* I/O space timing register 4 */ + + #define FSMC_PIO_IOHIZ (0xFF << 24) + #define FSMC_PIO_IOHOLD (0xFF << 16) + #define FSMC_PIO_IOWAIT (0xFF << 8) + #define FSMC_PIO_IOSET 0xF |