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Merge branch 'feature/refactor_crc' into 'master'

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Refactor CRC algorithm

See merge request sdk/ESP8266_RTOS_SDK!614
This commit is contained in:
Dong Heng
2019-04-01 16:59:04 +08:00
parent bc01a1d39c 17fc3ab6ba
commit 0460e53434
2 changed files with 84 additions and 2 deletions
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5
components/util/src/crc.c
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@ -15,6 +15,7 @@
#include <stdint.h>
#include "crc.h"
#include "ibus_data.h"
static const uint32_t crc32_le_table[256] = {
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L,
@ -113,7 +114,7 @@ uint16_t crc16_le(uint16_t crc, const uint8_t* buf, uint32_t len)
crc = ~crc;
for (i = 0; i < len; i++) {
crc = crc16_le_table[(crc ^ buf[i]) & 0xff] ^ (crc >> 8);
crc = ESP_IBUS_GET_U16_DATA((crc ^ buf[i]) & 0xff, crc16_le_table) ^ (crc >> 8);
}
return ~crc;
@ -137,7 +138,7 @@ uint8_t esp_crc8(uint8_t const* p, uint32_t len)
uint8_t crc = 0x00;
while (len--) {
crc = crc8_le_table[crc ^ *p++];
crc = ESP_IBUS_GET_U8_DATA(crc ^ *p++, crc8_le_table);
}
return crc;

81
components/util/test/test_crc.c Normal file
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@ -0,0 +1,81 @@
// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include <stdio.h>
#include <assert.h>
#include "crc.h"
#include "unity.h"
#define TEST_CRC_COUNT 4096
#define TEST_CRC_DEBUG 1
#define TEST_DATA_BYTES 128
static uint8_t s_crc_src[TEST_DATA_BYTES];
TEST_CASE("Test CRC8", "[CRC8]")
{
uint8_t crc = 0;
uint32_t crc_time = 0;
extern uint32_t esp_get_time(void);
memset(s_crc_src, 11, TEST_DATA_BYTES);
for (int i = 0; i < TEST_CRC_COUNT; i++) {
uint32_t tmp = esp_get_time();
crc = esp_crc8(s_crc_src, sizeof(s_crc_src));
crc_time += esp_get_time() - tmp;
TEST_ASSERT_EQUAL(0xd7, crc);
}
#if TEST_CRC_DEBUG
printf("CRC8 test cost time totally %u us, once cost is about %u us\n",
crc_time, crc_time / TEST_CRC_COUNT);
#endif
}
// no align: CRC8 test cost time totally 955287 us, once cost is about 233 us
// align : CRC8 test cost time totally 186694 us, once cost is about 45 us
TEST_CASE("Test CRC16", "[CRC16]")
{
uint16_t crc = 0;
uint32_t crc_time = 0;
extern uint32_t esp_get_time(void);
memset(s_crc_src, 11, TEST_DATA_BYTES);
for (int i = 0; i < TEST_CRC_COUNT; i++) {
uint32_t tmp = esp_get_time();
crc = crc16_le(0, s_crc_src, sizeof(s_crc_src));
crc_time += esp_get_time() - tmp;
TEST_ASSERT_EQUAL(0x495d, crc);
}
#if TEST_CRC_DEBUG
printf("CRC16 test cost time totally %u us, once cost is about %u us\n",
crc_time, crc_time / TEST_CRC_COUNT);
#endif
}
// no align: CRC16 test cost time totally 1114398 us, once cost is about 272 us
// align : CRC16 test cost time totally 200268 us, once cost is about 48 us