1 /**
2   ******************************************************************************
3   * @file    stm32g0xx_hal_crc_ex.c
4   * @author  MCD Application Team
5   * @brief   Extended CRC HAL module driver.
6   *          This file provides firmware functions to manage the extended
7   *          functionalities of the CRC peripheral.
8   *
9   @verbatim
10 ================================================================================
11             ##### How to use this driver #####
12 ================================================================================
13     [..]
14          (+) Set user-defined generating polynomial through HAL_CRCEx_Polynomial_Set()
15          (+) Configure Input or Output data inversion
16 
17   @endverbatim
18   ******************************************************************************
19   * @attention
20   *
21   * <h2><center>&copy; Copyright (c) 2018 STMicroelectronics.
22   * All rights reserved.</center></h2>
23   *
24   * This software component is licensed by ST under BSD 3-Clause license,
25   * the "License"; You may not use this file except in compliance with the
26   * License. You may obtain a copy of the License at:
27   *                        opensource.org/licenses/BSD-3-Clause
28   *
29   ******************************************************************************
30   */
31 
32 /* Includes ------------------------------------------------------------------*/
33 #include "stm32g0xx_hal.h"
34 
35 /** @addtogroup STM32G0xx_HAL_Driver
36   * @{
37   */
38 
39 /** @defgroup CRCEx CRCEx
40   * @brief CRC Extended HAL module driver
41   * @{
42   */
43 
44 #ifdef HAL_CRC_MODULE_ENABLED
45 
46 /* Private typedef -----------------------------------------------------------*/
47 /* Private define ------------------------------------------------------------*/
48 /* Private macro -------------------------------------------------------------*/
49 /* Private variables ---------------------------------------------------------*/
50 /* Private function prototypes -----------------------------------------------*/
51 /* Exported functions --------------------------------------------------------*/
52 
53 /** @defgroup CRCEx_Exported_Functions CRC Extended Exported Functions
54   * @{
55   */
56 
57 /** @defgroup CRCEx_Exported_Functions_Group1 Extended Initialization/de-initialization functions
58   * @brief    Extended Initialization and Configuration functions.
59   *
60 @verbatim
61  ===============================================================================
62             ##### Extended configuration functions #####
63  ===============================================================================
64     [..]  This section provides functions allowing to:
65       (+) Configure the generating polynomial
66       (+) Configure the input data inversion
67       (+) Configure the output data inversion
68 
69 @endverbatim
70   * @{
71   */
72 
73 
74 /**
75   * @brief  Initialize the CRC polynomial if different from default one.
76   * @param  hcrc CRC handle
77   * @param  Pol CRC generating polynomial (7, 8, 16 or 32-bit long).
78   *         This parameter is written in normal representation, e.g.
79   *         @arg for a polynomial of degree 7, X^7 + X^6 + X^5 + X^2 + 1 is written 0x65
80   *         @arg for a polynomial of degree 16, X^16 + X^12 + X^5 + 1 is written 0x1021
81   * @param  PolyLength CRC polynomial length.
82   *         This parameter can be one of the following values:
83   *          @arg @ref CRC_POLYLENGTH_7B  7-bit long CRC (generating polynomial of degree 7)
84   *          @arg @ref CRC_POLYLENGTH_8B  8-bit long CRC (generating polynomial of degree 8)
85   *          @arg @ref CRC_POLYLENGTH_16B 16-bit long CRC (generating polynomial of degree 16)
86   *          @arg @ref CRC_POLYLENGTH_32B 32-bit long CRC (generating polynomial of degree 32)
87   * @retval HAL status
88   */
HAL_CRCEx_Polynomial_Set(CRC_HandleTypeDef * hcrc,uint32_t Pol,uint32_t PolyLength)89 HAL_StatusTypeDef HAL_CRCEx_Polynomial_Set(CRC_HandleTypeDef *hcrc, uint32_t Pol, uint32_t PolyLength)
90 {
91   HAL_StatusTypeDef status = HAL_OK;
92   uint32_t msb = 31U; /* polynomial degree is 32 at most, so msb is initialized to max value */
93 
94   /* Check the parameters */
95   assert_param(IS_CRC_POL_LENGTH(PolyLength));
96 
97   /* check polynomial definition vs polynomial size:
98    * polynomial length must be aligned with polynomial
99    * definition. HAL_ERROR is reported if Pol degree is
100    * larger than that indicated by PolyLength.
101    * Look for MSB position: msb will contain the degree of
102    *  the second to the largest polynomial member. E.g., for
103    *  X^7 + X^6 + X^5 + X^2 + 1, msb = 6. */
104   while ((msb-- > 0U) && ((Pol & ((uint32_t)(0x1U) << (msb & 0x1FU))) == 0U))
105   {
106   }
107 
108   switch (PolyLength)
109   {
110     case CRC_POLYLENGTH_7B:
111       if (msb >= HAL_CRC_LENGTH_7B)
112       {
113         status =   HAL_ERROR;
114       }
115       break;
116     case CRC_POLYLENGTH_8B:
117       if (msb >= HAL_CRC_LENGTH_8B)
118       {
119         status =   HAL_ERROR;
120       }
121       break;
122     case CRC_POLYLENGTH_16B:
123       if (msb >= HAL_CRC_LENGTH_16B)
124       {
125         status =   HAL_ERROR;
126       }
127       break;
128 
129     case CRC_POLYLENGTH_32B:
130       /* no polynomial definition vs. polynomial length issue possible */
131       break;
132     default:
133       status =  HAL_ERROR;
134       break;
135   }
136   if (status == HAL_OK)
137   {
138     /* set generating polynomial */
139     WRITE_REG(hcrc->Instance->POL, Pol);
140 
141     /* set generating polynomial size */
142     MODIFY_REG(hcrc->Instance->CR, CRC_CR_POLYSIZE, PolyLength);
143   }
144   /* Return function status */
145   return status;
146 }
147 
148 /**
149   * @brief  Set the Reverse Input data mode.
150   * @param  hcrc CRC handle
151   * @param  InputReverseMode Input Data inversion mode.
152   *         This parameter can be one of the following values:
153   *          @arg @ref CRC_INPUTDATA_INVERSION_NONE     no change in bit order (default value)
154   *          @arg @ref CRC_INPUTDATA_INVERSION_BYTE     Byte-wise bit reversal
155   *          @arg @ref CRC_INPUTDATA_INVERSION_HALFWORD HalfWord-wise bit reversal
156   *          @arg @ref CRC_INPUTDATA_INVERSION_WORD     Word-wise bit reversal
157   * @retval HAL status
158   */
HAL_CRCEx_Input_Data_Reverse(CRC_HandleTypeDef * hcrc,uint32_t InputReverseMode)159 HAL_StatusTypeDef HAL_CRCEx_Input_Data_Reverse(CRC_HandleTypeDef *hcrc, uint32_t InputReverseMode)
160 {
161   /* Check the parameters */
162   assert_param(IS_CRC_INPUTDATA_INVERSION_MODE(InputReverseMode));
163 
164   /* Change CRC peripheral state */
165   hcrc->State = HAL_CRC_STATE_BUSY;
166 
167   /* set input data inversion mode */
168   MODIFY_REG(hcrc->Instance->CR, CRC_CR_REV_IN, InputReverseMode);
169   /* Change CRC peripheral state */
170   hcrc->State = HAL_CRC_STATE_READY;
171 
172   /* Return function status */
173   return HAL_OK;
174 }
175 
176 /**
177   * @brief  Set the Reverse Output data mode.
178   * @param  hcrc CRC handle
179   * @param  OutputReverseMode Output Data inversion mode.
180   *         This parameter can be one of the following values:
181   *          @arg @ref CRC_OUTPUTDATA_INVERSION_DISABLE no CRC inversion (default value)
182   *          @arg @ref CRC_OUTPUTDATA_INVERSION_ENABLE  bit-level inversion (e.g. for a 8-bit CRC: 0xB5 becomes 0xAD)
183   * @retval HAL status
184   */
HAL_CRCEx_Output_Data_Reverse(CRC_HandleTypeDef * hcrc,uint32_t OutputReverseMode)185 HAL_StatusTypeDef HAL_CRCEx_Output_Data_Reverse(CRC_HandleTypeDef *hcrc, uint32_t OutputReverseMode)
186 {
187   /* Check the parameters */
188   assert_param(IS_CRC_OUTPUTDATA_INVERSION_MODE(OutputReverseMode));
189 
190   /* Change CRC peripheral state */
191   hcrc->State = HAL_CRC_STATE_BUSY;
192 
193   /* set output data inversion mode */
194   MODIFY_REG(hcrc->Instance->CR, CRC_CR_REV_OUT, OutputReverseMode);
195 
196   /* Change CRC peripheral state */
197   hcrc->State = HAL_CRC_STATE_READY;
198 
199   /* Return function status */
200   return HAL_OK;
201 }
202 
203 
204 
205 
206 /**
207   * @}
208   */
209 
210 
211 /**
212   * @}
213   */
214 
215 
216 #endif /* HAL_CRC_MODULE_ENABLED */
217 /**
218   * @}
219   */
220 
221 /**
222   * @}
223   */
224 
225 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
226