mbed official / mbed-dev

mbed library sources. Supersedes mbed-src.

Dependents:   Nucleo_Hello_Encoder BLE_iBeaconScan AM1805_DEMO DISCO-F429ZI_ExportTemplate1 ... more

targets/TARGET_NUVOTON/nu_timer.h@189:f392fc9709a3, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 22:31:08 2019 +0000
Revision:
189:f392fc9709a3
Parent:
188:bcfe06ba3d64 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Anna Bridge 180:96ed750bd169 1 /* mbed Microcontroller Library
Anna Bridge 180:96ed750bd169 2 * Copyright (c) 2015-2016 Nuvoton
Anna Bridge 180:96ed750bd169 3 *
Anna Bridge 180:96ed750bd169 4 * Licensed under the Apache License, Version 2.0 (the "License");
Anna Bridge 180:96ed750bd169 5 * you may not use this file except in compliance with the License.
Anna Bridge 180:96ed750bd169 6 * You may obtain a copy of the License at
Anna Bridge 180:96ed750bd169 7 *
Anna Bridge 180:96ed750bd169 8 * http://www.apache.org/licenses/LICENSE-2.0
Anna Bridge 180:96ed750bd169 9 *
Anna Bridge 180:96ed750bd169 10 * Unless required by applicable law or agreed to in writing, software
Anna Bridge 180:96ed750bd169 11 * distributed under the License is distributed on an "AS IS" BASIS,
Anna Bridge 180:96ed750bd169 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
Anna Bridge 180:96ed750bd169 13 * See the License for the specific language governing permissions and
Anna Bridge 180:96ed750bd169 14 * limitations under the License.
Anna Bridge 180:96ed750bd169 15 */
Anna Bridge 180:96ed750bd169 16
Anna Bridge 180:96ed750bd169 17 #ifndef NU_TIMER_H
Anna Bridge 180:96ed750bd169 18 #define NU_TIMER_H
Anna Bridge 180:96ed750bd169 19
Anna Bridge 180:96ed750bd169 20 #include <stdint.h>
Anna Bridge 180:96ed750bd169 21 #include <stdbool.h>
Anna Bridge 180:96ed750bd169 22 #include "cmsis.h"
Anna Bridge 180:96ed750bd169 23 #include "ticker_api.h"
Anna Bridge 180:96ed750bd169 24 #include "us_ticker_api.h"
Anna Bridge 180:96ed750bd169 25
Anna Bridge 180:96ed750bd169 26 #ifdef __cplusplus
Anna Bridge 180:96ed750bd169 27 extern "C" {
Anna Bridge 180:96ed750bd169 28 #endif
Anna Bridge 180:96ed750bd169 29
Anna Bridge 180:96ed750bd169 30 /* A simple count-down timer used for Nuvoton ported drivers
Anna Bridge 180:96ed750bd169 31 *
Anna Bridge 180:96ed750bd169 32 * NOTE: nu_countdown_init must be paired with nu_countdown_free.
Anna Bridge 180:96ed750bd169 33 *
Anna Bridge 180:96ed750bd169 34 * Example:
Anna Bridge 180:96ed750bd169 35 * nu_countdown_ctx_s ctx;
Anna Bridge 180:96ed750bd169 36 *
Anna Bridge 180:96ed750bd169 37 * // Set up 2 ms timeout
Anna Bridge 180:96ed750bd169 38 * nu_countdown_init(&ctx, 2000);
Anna Bridge 180:96ed750bd169 39 *
Anna Bridge 180:96ed750bd169 40 * // Timed-wait for a task
Anna Bridge 180:96ed750bd169 41 * while (true) {
Anna Bridge 180:96ed750bd169 42 * // Poll the task
Anna Bridge 180:96ed750bd169 43 *
Anna Bridge 180:96ed750bd169 44 * if (nu_countdown_expired(&ctx)) {
Anna Bridge 180:96ed750bd169 45 * // Timeout
Anna Bridge 180:96ed750bd169 46 * }
Anna Bridge 180:96ed750bd169 47 * }
Anna Bridge 180:96ed750bd169 48 *
Anna Bridge 180:96ed750bd169 49 * // Must pair nu_countdown_init with nu_countdown_free in the end
Anna Bridge 180:96ed750bd169 50 * nu_countdown_free(&ctx);
Anna Bridge 180:96ed750bd169 51 */
Anna Bridge 180:96ed750bd169 52
Anna Bridge 180:96ed750bd169 53 struct nu_countdown_ctx_s {
Anna Bridge 180:96ed750bd169 54 const ticker_data_t * _ticker_data; // Hold ticker_data_t
Anna Bridge 180:96ed750bd169 55 us_timestamp_t _interval_end_us; // End of interval in us
Anna Bridge 180:96ed750bd169 56 bool _expired; // Expired or not
Anna Bridge 180:96ed750bd169 57 };
Anna Bridge 180:96ed750bd169 58
AnnaBridge 188:bcfe06ba3d64 59 void nu_countdown_init(struct nu_countdown_ctx_s *ctx, us_timestamp_t interval_us);
AnnaBridge 188:bcfe06ba3d64 60 bool nu_countdown_expired(struct nu_countdown_ctx_s *ctx);
AnnaBridge 188:bcfe06ba3d64 61 void nu_countdown_free(struct nu_countdown_ctx_s *ctx);
AnnaBridge 188:bcfe06ba3d64 62
Anna Bridge 180:96ed750bd169 63
AnnaBridge 188:bcfe06ba3d64 64 /* Replacement for wait_us when intermediary us ticker layer is disabled
AnnaBridge 188:bcfe06ba3d64 65 *
AnnaBridge 188:bcfe06ba3d64 66 * Use of wait_us directly from the low power ticker causes the system to deadlock during
AnnaBridge 188:bcfe06ba3d64 67 * the sleep test because the sleep test disables the intermediary us ticker layer during
AnnaBridge 188:bcfe06ba3d64 68 * the test.
AnnaBridge 188:bcfe06ba3d64 69 *
AnnaBridge 188:bcfe06ba3d64 70 * To prevent this lockup, nu_busy_wait_us is created to replace wait_us, which uses the us ticker
AnnaBridge 188:bcfe06ba3d64 71 * directly rather than go though the intermediary us ticker layer.
AnnaBridge 188:bcfe06ba3d64 72 *
AnnaBridge 188:bcfe06ba3d64 73 * During wait period through nu_busy_wait_us, CPU would be busy spinning.
AnnaBridge 188:bcfe06ba3d64 74 */
AnnaBridge 188:bcfe06ba3d64 75 void nu_busy_wait_us(uint32_t us);
Anna Bridge 180:96ed750bd169 76
AnnaBridge 188:bcfe06ba3d64 77 /* Delay 4 cycles per round by hand-counting instruction cycles */
AnnaBridge 188:bcfe06ba3d64 78 void nu_delay_cycle_x4(uint32_t rounds);
Anna Bridge 180:96ed750bd169 79
Anna Bridge 180:96ed750bd169 80 #ifdef __cplusplus
Anna Bridge 180:96ed750bd169 81 }
Anna Bridge 180:96ed750bd169 82 #endif
Anna Bridge 180:96ed750bd169 83
Anna Bridge 180:96ed750bd169 84 #endif