1 /* 2 * Copyright (c) 2018-2019 Nordic Semiconductor ASA 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #define EVENT_OVERHEAD_XTAL_US 1500 8 #define EVENT_OVERHEAD_PREEMPT_US 0 /* if <= min, then dynamic preempt */ 9 #define EVENT_OVERHEAD_PREEMPT_MIN_US 0 10 #define EVENT_OVERHEAD_PREEMPT_MAX_US EVENT_OVERHEAD_XTAL_US 11 12 /* Measurement based on drifting roles that can overlap leading to collision 13 * resolutions that consume CPU time between radio events. 14 * Value include max end, start and scheduling CPU usage times. 15 * Measurements based on central_gatt_write and peripheral_gatt_write sample on 16 * nRF52833 SoC. 17 */ 18 #if defined(CONFIG_BT_CTLR_ADV_EXT) 19 #if defined(CONFIG_BT_OBSERVER) 20 #if defined(CONFIG_BT_CTLR_PHY_CODED) 21 /* Active connection in peripheral role with extended scanning on 1M and Coded 22 * PHY, scheduling and receiving auxiliary PDUs. 23 */ 24 #define EVENT_OVERHEAD_START_US 733 /* 24 RTC ticks */ 25 #else /* !CONFIG_BT_CTLR_PHY_CODED */ 26 /* Active connection in peripheral role with extended scanning on 1M only, 27 * scheduling and receiving auxiliary PDUs. 28 */ 29 #define EVENT_OVERHEAD_START_US 428 /* 14 RTC ticks */ 30 #endif /* !CONFIG_BT_CTLR_PHY_CODED */ 31 #else /* !CONFIG_BT_OBSERVER */ 32 /* Active connection in peripheral role with legacy scanning on 1M. 33 */ 34 #define EVENT_OVERHEAD_START_US 275 /* 9 RTC ticks */ 35 #endif /* !CONFIG_BT_OBSERVER */ 36 #else /* !CONFIG_BT_CTLR_ADV_EXT */ 37 /* Active connection in peripheral role with additional advertising state. 38 */ 39 #define EVENT_OVERHEAD_START_US 275 /* 9 RTC ticks */ 40 #endif /* !CONFIG_BT_CTLR_ADV_EXT */ 41 42 /* Worst-case time margin needed after event end-time in the air 43 * (done/preempt race margin + power-down/chain delay) 44 */ 45 #define EVENT_OVERHEAD_END_US 40 46 47 /* Sleep Clock Accuracy */ 48 #define EVENT_JITTER_US 16 49 50 /* Inter-Event Space (IES) */ 51 #define EVENT_TIES_US 625 52 53 /* Ticker resolution margin 54 * Needed due to the lack of fine timing resolution in ticker_start 55 * and ticker_update. Set to 32 us, which is ~1 tick with 32768 Hz 56 * clock. 57 */ 58 #define EVENT_TICKER_RES_MARGIN_US 32 59 60 #define EVENT_RX_JITTER_US(phy) 16 /* Radio Rx timing uncertainty */ 61 #define EVENT_RX_TO_US(phy) ((((((phy)&0x03) + 4)<<3)/BIT((((phy)&0x3)>>1))) + \ 62 EVENT_RX_JITTER_US(phy)) 63 64 /* Turnaround time between RX and TX is based on CPU execution speed. It also 65 * includes radio ramp up time. The value must meet hard deadline of `150 us` 66 * imposed by BT Core spec for inter frame spacing (IFS). To include CPUs with 67 * slow clock, the conservative approach was taken to use IFS value for all 68 * cases. 69 */ 70 #define EVENT_RX_TX_TURNAROUND(phy) 150 71 72 /* Sub-microsecond conversion macros. With current timer resolution of ~30 us 73 * per tick, conversion factor is 1, and macros map 1:1 between us_frac and us. 74 * On sub-microsecond tick resolution architectures, a number of bits may be 75 * used to represent fractions of a microsecond, to allow higher precision in 76 * window widening. 77 */ 78 #define EVENT_US_TO_US_FRAC(us) (us) 79 #define EVENT_US_FRAC_TO_US(us_frac) (us_frac) 80 #define EVENT_TICKS_TO_US_FRAC(ticks) HAL_TICKER_TICKS_TO_US(ticks) 81 #define EVENT_US_FRAC_TO_TICKS(us_frac) HAL_TICKER_US_TO_TICKS(us_frac) 82 #define EVENT_US_FRAC_TO_REMAINDER(us_frac) HAL_TICKER_REMAINDER(us_frac) 83 84 /* Time needed to set up a CIS from ACL instant to prepare (incl. radio). Used 85 * for CIS_Offset_Min. 86 */ 87 #define EVENT_OVERHEAD_CIS_SETUP_US MAX(EVENT_OVERHEAD_START_US, 500U) 88
