In DSPS device project

step 1:
extern const struct ke_msg_handler user_spss_process_handlers[]=
{
{SPS_SERVER_CREATE_DB_CFM, (ke_msg_func_t)user_sps_create_db_cfm_handler},
{SPS_SERVER_ENABLE_CFM, (ke_msg_func_t)user_sps_server_enable_cfm_handler},
{SPS_SERVER_DATA_TX_CFM, (ke_msg_func_t)user_sps_server_data_tx_cfm_handler},
{SPS_SERVER_DATA_RX_IND, (ke_msg_func_t)user_sps_server_data_rx_ind_handler},
{SPS_SERVER_TX_FLOW_CTRL_IND, (ke_msg_func_t)user_sps_server_tx_flow_ctrl_ind_handler},
{SPS_SERVER_ERROR_IND, (ke_msg_func_t)user_sps_server_error_ind_handler},
{APP_SAMPLE128_TIMER, (ke_msg_func_t)sample128_timer_handler},
};

step 2:
int sample128_timer_handler(ke_msg_id_t const msgid,
void const *param,
ke_task_id_t const dest_id,
ke_task_id_t const src_id); // Declaration

step 3:
int sample128_timer_handler(ke_msg_id_t const msgid,
void const *param,
ke_task_id_t const dest_id,
ke_task_id_t const src_id) // Definition
{

app_timer_set(APP_SAMPLE128_TIMER,TASK_APP,600);

return (KE_MSG_CONSUMED);
}

step 4 : timer call

void user_ble_pull (bool init, bool success)
{
if(init)
{
app_timer_set(APP_SAMPLE128_TIMER,TASK_APP,600);
user_send_ble_data(p_data, length);
}
else {
user_send_ble_data(p_data, length);
}
}

PROBLEM :
code always stops here .... /** hardfault_handeler **/....
if ((GetWord16(SYS_STAT_REG) & DBG_IS_UP) == DBG_IS_UP)
__asm("BKPT #0\n");
else
while(1);

what could be the problem...am i doing it right way ??