CRC8/16: 16 elements table support added

pstolarz · Sep 1, 2024 · b7b1f25 · b7b1f25
1 parent 880fa42
commit b7b1f25
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Showing 4 changed files with 48 additions and 15 deletions.
diff --git a/Kconfig b/Kconfig
@@ -33,6 +33,8 @@ choice CRC8_ALGO
         bool "Basic; no memory tables"
     config CRC8_ALGO_TAB_16LH
         bool "2x16 elements table"
+    config CRC8_ALGO_TAB_16
+        bool "16 elements table"
 endchoice
 
 config CRC16_ENABLED
@@ -48,6 +50,8 @@ choice CRC16_ALGO
         bool "Basic; no memory tables"
     config CRC16_ALGO_TAB_16LH
         bool "2x16 elements table"
+    config CRC16_ALGO_TAB_16
+        bool "16 elements table"
 endchoice
 endif
 

diff --git a/keywords.txt b/keywords.txt
@@ -154,7 +154,7 @@ CONFIG_PWR_CTRL_REV_POLARITY	LITERAL1
 CONFIG_SEARCH_ENABLED	LITERAL1
 CONFIG_MAX_SEARCH_FILTERS	LITERAL1
 CONFIG_OVERDRIVE_ENABLED	LITERAL1
-CONFIG_CRC8_ALGO CRC8_TAB_16LH	LITERAL1
+CONFIG_CRC8_ALGO	LITERAL1
 CONFIG_CRC16_ENABLED	LITERAL1
 CONFIG_CRC16_ALGO	LITERAL1
 CONFIG_FLASH_CRC_TAB	LITERAL1
@@ -170,8 +170,10 @@ CONFIG_RP2040_PIOSM_NUM_USED	LITERAL1
 
 CRC8_BASIC	LITERAL1
 CRC8_TAB_16LH	LITERAL1
+CRC8_TAB_16	LITERAL1
 CRC16_BASIC	LITERAL1
 CRC16_TAB_16LH	LITERAL1
+CRC16_TAB_16	LITERAL1
 
 TIMING_STRICT	LITERAL1
 TIMING_RELAXED	LITERAL1

diff --git a/src/OneWireNg.cpp b/src/OneWireNg.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023 Piotr Stolarz
+ * Copyright (c) 2019-2024 Piotr Stolarz
  * OneWireNg: Arduino 1-wire service library
  *
  * Distributed under the 2-clause BSD License (the License)
@@ -15,17 +15,23 @@
 
 #define CRC8_BASIC      1
 #define CRC8_TAB_16LH   2
+#define CRC8_TAB_16     3
 
 #define CRC16_BASIC     1
 #define CRC16_TAB_16LH  2
+#define CRC16_TAB_16    3
 
 #if defined(CONFIG_CRC8_ALGO) && \
-    !(CONFIG_CRC8_ALGO == CRC8_BASIC || CONFIG_CRC8_ALGO == CRC8_TAB_16LH)
+    !(CONFIG_CRC8_ALGO == CRC8_BASIC || \
+      CONFIG_CRC8_ALGO == CRC8_TAB_16LH || \
+      CONFIG_CRC8_ALGO == CRC8_TAB_16)
 # error "Invalid CONFIG_CRC8_ALGO"
 #endif
 
 #if defined(CONFIG_CRC16_ALGO) && \
-    !(CONFIG_CRC16_ALGO == CRC16_BASIC || CONFIG_CRC16_ALGO == CRC16_TAB_16LH)
+    !(CONFIG_CRC16_ALGO == CRC16_BASIC || \
+      CONFIG_CRC16_ALGO == CRC16_TAB_16LH || \
+      CONFIG_CRC16_ALGO == CRC16_TAB_16)
 # error "Invalid CONFIG_CRC16_ALGO"
 #endif
 
@@ -292,22 +298,29 @@ uint8_t OneWireNg::crc8(const void *in, size_t len, uint8_t crc_in)
 {
     uint8_t crc = crc_in;
 
-#if (CONFIG_CRC8_ALGO == CRC8_TAB_16LH)
+#if (CONFIG_CRC8_ALGO == CRC8_TAB_16LH || CONFIG_CRC8_ALGO == CRC8_TAB_16)
     const uint8_t *in_bts = (const uint8_t*)in;
 
+# if (CONFIG_CRC8_ALGO == CRC8_TAB_16LH)
     CRCTAB_STORAGE static uint8_t CRC8_16L[] = {
         0x00, 0x5e, 0xbc, 0xe2, 0x61, 0x3f, 0xdd, 0x83,
         0xc2, 0x9c, 0x7e, 0x20, 0xa3, 0xfd, 0x1f, 0x41
     };
+# endif
     CRCTAB_STORAGE static uint8_t CRC8_16H[] = {
         0x00, 0x9d, 0x23, 0xbe, 0x46, 0xdb, 0x65, 0xf8,
         0x8c, 0x11, 0xaf, 0x32, 0xca, 0x57, 0xe9, 0x74
     };
 
     while (len--) {
         crc ^= *in_bts++;
-        crc = tabRead_u8(CRC8_16L + (crc & 0x0f)) ^
-            tabRead_u8(CRC8_16H + (crc >> 4));
+# if (CONFIG_CRC8_ALGO == CRC8_TAB_16LH)
+        uint8_t tl = tabRead_u8(CRC8_16L + (crc & 0xf));
+# else
+        uint8_t tl = tabRead_u8(CRC8_16H + (crc & 0xf));
+        tl = tabRead_u8(CRC8_16H + (tl & 0xf)) ^ (tl >> 4);
+# endif
+        crc = tl ^ tabRead_u8(CRC8_16H + (crc >> 4));
     }
 #else
     crc = OneWireNg::crc<uint8_t, 0x8c>(in, len, crc);
@@ -320,23 +333,29 @@ uint16_t OneWireNg::crc16(const void *in, size_t len, uint16_t crc_in)
 {
     uint16_t crc = crc_in;
 
-# if (CONFIG_CRC16_ALGO == CRC16_TAB_16LH)
+# if (CONFIG_CRC16_ALGO == CRC16_TAB_16LH || CONFIG_CRC16_ALGO == CRC16_TAB_16)
     const uint8_t *in_bts = (const uint8_t*)in;
 
+# if (CONFIG_CRC16_ALGO == CRC16_TAB_16LH)
     CRCTAB_STORAGE static uint16_t CRC16_16L[] = {
         0x0000, 0xc0c1, 0xc181, 0x0140, 0xc301, 0x03c0, 0x0280, 0xc241,
         0xc601, 0x06c0, 0x0780, 0xc741, 0x0500, 0xc5c1, 0xc481, 0x0440
     };
+#endif
     CRCTAB_STORAGE static uint16_t CRC16_16H[] = {
         0x0000, 0xcc01, 0xd801, 0x1400, 0xf001, 0x3c00, 0x2800, 0xe401,
         0xa001, 0x6c00, 0x7800, 0xb401, 0x5000, 0x9c01, 0x8801, 0x4400
     };
 
     while (len--) {
         crc ^= *in_bts++;
-        crc = (crc >> 8) ^
-            tabRead_u16(CRC16_16L + (crc & 0x0f)) ^
-            tabRead_u16(CRC16_16H + ((crc >> 4) & 0x0f));
+# if (CONFIG_CRC16_ALGO == CRC16_TAB_16LH)
+        uint16_t tl = tabRead_u16(CRC16_16L + (crc & 0xf));
+# else
+        uint16_t tl = tabRead_u16(CRC16_16H + (crc & 0xf));
+        tl = tabRead_u16(CRC16_16H + (tl & 0xf)) ^ (tl >> 4);
+# endif
+        crc = (crc >> 8) ^ tl ^ tabRead_u16(CRC16_16H + ((crc >> 4) & 0xf));
     }
 # else
     crc = OneWireNg::crc<uint16_t, 0xa001>(in, len, crc_in);

diff --git a/src/OneWireNg_Config.h b/src/OneWireNg_Config.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023 Piotr Stolarz
+ * Copyright (c) 2019-2024 Piotr Stolarz
  * OneWireNg: Arduino 1-wire service library
  *
  * Distributed under the 2-clause BSD License (the License)
@@ -42,12 +42,16 @@
 #  define CONFIG_CRC8_ALGO CRC8_BASIC
 # elif CONFIG_CRC8_ALGO_TAB_16LH
 #  define CONFIG_CRC8_ALGO CRC8_TAB_16LH
+# elif CONFIG_CRC8_ALGO_TAB_16
+#  define CONFIG_CRC8_ALGO CRC8_TAB_16
 # endif
 
 # if CONFIG_CRC16_ALGO_BASIC
 #  define CONFIG_CRC16_ALGO CRC16_BASIC
 # elif CONFIG_CRC16_ALGO_TAB_16LH
 #  define CONFIG_CRC16_ALGO CRC16_TAB_16LH
+# elif CONFIG_CRC16_ALGO_TAB_16
+#  define CONFIG_CRC16_ALGO CRC16_TAB_16
 # endif
 
 # if CONFIG_BITBANG_TIMING_STRICT
@@ -137,9 +141,11 @@
  * Type of algorithm used for CRC-8/MAXIM calculation.
  *
  * The macro may be defined as:
- * - @c CRC8_BASIC: Basic method. No memory tables used. This method is
- *   about 8 times slower than the tabled method but no extra memory is used.
+ * - @c CRC8_BASIC: Basic method. No memory tables used. This method is about
+ *   8 times slower than the table based methods but no extra memory is used.
  * - @c CRC8_TAB_16LH: 2x16 elements table, 1 byte each.
+ * - @c CRC8_TAB_16: 16 elements table, 1 byte each. This method is about 20%
+ *   slower than 2x16 elements table based method.
  */
 # ifndef CONFIG_CRC8_ALGO
 #  define CONFIG_CRC8_ALGO CRC8_TAB_16LH
@@ -158,8 +164,10 @@
  *
  * The macro may be defined as:
  * - @c CRC16_BASIC: Basic method. No memory tables used. This method is about
- *     8 times slower than the tabled method but no extra memory is used.
+ *   8 times slower than the table based methods but no extra memory is used.
  * - @c CRC16_TAB_16LH: 2x16 elements table, 2 bytes each.
+ * - @c CRC16_TAB_16: 16 elements table, 2 bytes each. This method is about 20%
+ *   slower than 2x16 elements table based method.
  */
 # ifndef CONFIG_CRC16_ALGO
 #  define CONFIG_CRC16_ALGO CRC16_TAB_16LH