试验用gpmc总线片选2外接FPGA,采用地址、数据复用,同步访问的模式。总线位宽使用16位方式:
引脚定义如下:
static struct pinmux_config fpga_pin_mux[] = {
{"gpmc_ad0.gpmc_ad0", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad1.gpmc_ad1", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad2.gpmc_ad2", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad3.gpmc_ad3", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad4.gpmc_ad4", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad5.gpmc_ad5", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad6.gpmc_ad6", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad7.gpmc_ad7", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad8.gpmc_ad8", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad9.gpmc_ad9", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad10.gpmc_ad10", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad11.gpmc_ad11", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad12.gpmc_ad12", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad13.gpmc_ad13", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad14.gpmc_ad14", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_ad15.gpmc_ad15", OMAP_MUX_MODE0 | AM33XX_PIN_INPUT_PULLUP},
{"gpmc_csn2.gpmc_csn2", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_advn_ale.gpmc_advn_ale", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_oen_ren.gpmc_oen_ren", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{"gpmc_wen.gpmc_wen", OMAP_MUX_MODE0 | AM33XX_PULL_DISA},
{NULL, 0},
};
Config1~7配置配置如下,异步模式,执行FPGA读操作,可以在ad0和cs抓取到信号,
GPMC_CONFIG1 0x00611200
GPMC_CONFIG2 0x00070900
GPMC_CONFIG3 0x00000000
GPMC_CONFIG4 0x06010701
GPMC_CONFIG5 0x0009070C
GPMC_CONFIG6 0x08000000
GPMC_CONFIG1 0x00000F41
改为异步模式,config1修改为0x28001200,执行FPGA读操作,ad0和CS无法抓取信号
同步模式相对异步模式还需要做那些参数修改,多谢!
yongqing wang:
发个帖子给你参考:blog.csdn.net/…/66970145