diff options
Diffstat (limited to 'libmaple/fsmc.c')
| -rw-r--r-- | libmaple/fsmc.c | 56 |
1 files changed, 29 insertions, 27 deletions
diff --git a/libmaple/fsmc.c b/libmaple/fsmc.c index 502b7b4..301a90d 100644 --- a/libmaple/fsmc.c +++ b/libmaple/fsmc.c @@ -1,5 +1,4 @@ - -/* ***************************************************************************** +/****************************************************************************** * The MIT License * * Copyright (c) 2010 Bryan Newbold. @@ -21,26 +20,27 @@ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. - * ****************************************************************************/ + *****************************************************************************/ #include "libmaple.h" #include "rcc.h" #include "gpio.h" #include "fsmc.h" -// These values determined for a particular SRAM chip by following the -// calculations in the ST FSMC application note. +/* These values determined for a particular SRAM chip by following the + * calculations in the ST FSMC application note. */ #define FSMC_ADDSET 0x0 #define FSMC_DATAST 0x3 -// Sets up the FSMC peripheral to use the SRAM chip on the maple native as an -// external segment of system memory space. -// This implementation is for the IS62WV51216BLL 8mbit chip (55ns timing) +/* Sets up the FSMC peripheral to use the SRAM chip on the maple + * native as an external segment of system memory space. This + * implementation is for the IS62WV51216BLL 8mbit chip (55ns + * timing) */ void fsmc_native_sram_init(void) { FSMC_Bank *bank; - // First we setup all the GPIO pins. - // Data lines... + /* First we setup all the GPIO pins. */ + /* Data lines... */ gpio_set_mode(GPIOD_BASE, 0, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOD_BASE, 1, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOD_BASE, 8, MODE_AF_OUTPUT_PP); @@ -57,7 +57,8 @@ void fsmc_native_sram_init(void) { gpio_set_mode(GPIOE_BASE, 13, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOE_BASE, 14, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOE_BASE, 15, MODE_AF_OUTPUT_PP); - // Address lines... + + /* Address lines... */ gpio_set_mode(GPIOD_BASE, 11, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOD_BASE, 12, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOD_BASE, 13, MODE_AF_OUTPUT_PP); @@ -77,7 +78,8 @@ void fsmc_native_sram_init(void) { gpio_set_mode(GPIOG_BASE, 3, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOG_BASE, 4, MODE_AF_OUTPUT_PP); gpio_set_mode(GPIOG_BASE, 5, MODE_AF_OUTPUT_PP); - // And control lines... + + /* And control lines... */ gpio_set_mode(GPIOD_BASE, 4, MODE_AF_OUTPUT_PP); // NOE gpio_set_mode(GPIOD_BASE, 5, MODE_AF_OUTPUT_PP); // NWE @@ -88,41 +90,41 @@ void fsmc_native_sram_init(void) { gpio_set_mode(GPIOE_BASE, 0, MODE_AF_OUTPUT_PP); // NBL0 gpio_set_mode(GPIOE_BASE, 1, MODE_AF_OUTPUT_PP); // NBL1 - - // Next enable the clock + + /* Next enable the clock */ rcc_clk_enable(RCC_FSMC); - // Then we configure channel 1 the FSMC SRAM peripheral - // (all SRAM channels are in "Bank 1" of the FSMC) + /* Then we configure channel 1 the FSMC SRAM peripheral (all SRAM + * channels are in "Bank 1" of the FSMC) */ bank = (FSMC_Bank*)(FSMC1_BASE); - - // Everything else is cleared (BCR1) + + /* Everything else is cleared (BCR1) */ bank->BCR = 0x0000; - // Memory type is SRAM + /* Memory type is SRAM */ bank->BCR &= ~(FSMC_BCR_MTYP); // '00' - // Databus width is 16bits - bank->BCR &= ~(FSMC_BCR_MWID); + /* Databus width is 16bits */ + bank->BCR &= ~(FSMC_BCR_MWID); bank->BCR |= 0x1 << 4; // '01' - // Memory is nonmultiplexed + /* Memory is nonmultiplexed */ bank->BCR &= ~(FSMC_BCR_MUXEN); // '0' - // Need write enable to write to the chip + /* Need write enable to write to the chip */ bank->BCR |= FSMC_BCR_WREN; - // Set ADDSET + /* Set ADDSET */ bank->BTR &= ~(FSMC_BTR_ADDSET); bank->BTR |= (FSMC_BTR_ADDSET | FSMC_ADDSET); - // Set DATAST + /* Set DATAST */ bank->BTR &= ~(FSMC_BTR_DATAST); bank->BTR |= (FSMC_BTR_DATAST | (FSMC_DATAST << 8)); - // Enable channel 1 + /* Enable channel 1 */ bank->BCR |= FSMC_BCR_MBKEN; // '1' - // FSMC_BWTR3 not used for this simple configuration. + /* (FSMC_BWTR3 not used for this simple configuration.) */ } |