上电时序:
Mmc_power_up()
Sdhci_set_ios()
Sdhci_set_power()
Sdhci_writeb(host,pwr,SDHC
I_POWER_CONTROLER)
启动流程:
Mmc_go_idle() CMD0
Idle state
Mmc_send_app_op() CMD1
Ready state
Mmc_all_send_cid() CMD2
Identification state
Mmc_send_relative_add()
CMD3
Stand__by state
Mmc_select_card() CMD7
Transfer state
mmc_get_ext_csd(card, &ext_csd)
CMD8
mmc_switch
mmc_set_timing
mmc_set_clock(host, max_dtr)