/* Toggle the card between the standby and transfer states.  */
int card_enter_trans(uint32_t instance)
/* Toggle the card between the standby and transfer states.  */
int card_enter_trans(uint32_t instance)
{
    command_t cmd;
    int card_address, port, status = FAIL;
    port = card_get_port(instance);
    card_address = usdhc_device[port].rca << RCA_SHIFT;
    card_cmd_config(&cmd, CMD7, card_address, READ, RESPONSE_48_CHECK_BUSY,
                    DATA_PRESENT_NONE, TRUE, TRUE);
    usdhc_printf("Send CMD7.\n");
    if (host_send_cmd(instance, &cmd) == SUCCESS) {
        if (card_trans_status(instance) == SUCCESS) {
            status = SUCCESS;
        }
    }
    return status;
}