How do I unblock the CPU with the S110 v7.1.0?
How do I unblock the CPU with the S110 v7.1.0?
Hi,
To disable the CPU blocking with S110 v7.1.0 or newer, you will have to use this API call:
/**@brief Set a BLE option.
*
* @details This call allows the application to set the value of an option.
*
* @param[in] opt_id Option ID.
* @param[in] p_opt Pointer to a ble_opt_t structure containing the option value.
*
* @retval ::NRF_SUCCESS Option set successfully.
* @retval ::NRF_ERROR_INVALID_ADDR Invalid pointer supplied.
* @retval ::BLE_ERROR_INVALID_CONN_HANDLE Invalid Connection Handle.
* @retval ::NRF_ERROR_INVALID_PARAM Invalid parameter(s) supplied, check parameter limits and constraints.
* @retval ::NRF_ERROR_INVALID_STATE Unable to set the parameter at this time.
* @retval ::NRF_ERROR_BUSY The stack is busy or the previous procedure has not completed.
*/
SVCALL(SD_BLE_OPT_SET, uint32_t, sd_ble_opt_set(uint32_t opt_id, ble_opt_t const *p_opt));
The options available as of now is only one, which is the mutual exclusion of radio activity and CPU usage (read block/unblock CPU in connection interval):
/**@brief Common Option IDs.
* IDs that uniquely identify a common option.
*/
enum BLE_COMMON_OPTS
{
BLE_COMMON_OPT_RADIO_CPU_MUTEX = BLE_OPT_BASE /**< Radio CPU mutex option. @ref ble_common_opt_radio_cpu_mutex_t */
};
And here's a small snippet on how to disable the CPU blocking:
uint32_t opt_id = BLE_COMMON_OPT_RADIO_CPU_MUTEX;
ble_opt_t cpu_blocking_enabled;
cpu_blocking_enabled.common_opt.radio_cpu_mutex.enable = 0;
ble_stack_init();
err_code = sd_ble_opt_set(opt_id, &cpu_blocking_enabled);
/* continue init */
Cheers, Håkon
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Additional images showing how the CPU availability is improved when advertising (same applies when in connection):
Before (CPU blocked during radio active):
After (Concurrent CPU when radio is active):
Black part showing the latency when CPU is blocked. [ADDED]: On the second trace, the CPU is still blocked at some periods because it's the softdevice active and preparing the radio packet, no the radio itself.
Cheers,
Hung Bui
