Standard test vector
CRC implementations are commonly verified with the ASCII input 123456789.
- Input format
- ASCII
- Input
- 123456789
- Expected CRC
- 0xA1
- Residue
- 0x00
CRC-8 / MAXIM-DOW
Width8-bitRefInYesRefOutYesInput data9 bytesUTF-8 bytesText is converted to UTF-8 bytes.
Standard test string
Result
Similar CRC Algorithms
5 modelsBrowse all algorithms
Result is calculated from the current input. Check is the published verification value for the standard input 123456789. Click another algorithm to view its detail page.
CRC-8 / BLUETOOTH
8-bitPoly 0xA7In Yes Out Yes
Result
0x26
Check
0x26
CRC-8 / DARC
8-bitPoly 0x39In Yes Out Yes
Result
0x15
Check
0x15
CRC-8 / MAXIM-DOW Current
8-bitPoly 0x31In Yes Out Yes
Result
0xA1
Check
0xA1
CRC-8 / NRSC-5
8-bitPoly 0x31In No Out No
Result
0xF7
Check
0xF7
CRC-8 / WCDMA
8-bitPoly 0x9BIn Yes Out Yes
Result
0x25
Check
0x25
CRC Lookup Table
CRC-8 / MAXIM-DOW · Poly 0x31 · Init 0x00 · XorOut 0x00 · 256 entries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 Source Code
CRC-8 / MAXIM-DOW · Poly 0x31 · Init 0x00 · XorOut 0x00 · C · 56 lines
/*
* Model: CRC-8 / MAXIM-DOW (8-bit)
* Poly: 0x31, Init: 0x00, XorOut: 0x00
* CRC Table C Source Code & Lookup Table Generator
*/
#include <stdint.h>
#include <stddef.h>
const uint8_t crc_table[256] = {
0x00, 0x5E, 0xBC, 0xE2, 0x61, 0x3F, 0xDD, 0x83,
0xC2, 0x9C, 0x7E, 0x20, 0xA3, 0xFD, 0x1F, 0x41,
0x9D, 0xC3, 0x21, 0x7F, 0xFC, 0xA2, 0x40, 0x1E,
0x5F, 0x01, 0xE3, 0xBD, 0x3E, 0x60, 0x82, 0xDC,
0x23, 0x7D, 0x9F, 0xC1, 0x42, 0x1C, 0xFE, 0xA0,
0xE1, 0xBF, 0x5D, 0x03, 0x80, 0xDE, 0x3C, 0x62,
0xBE, 0xE0, 0x02, 0x5C, 0xDF, 0x81, 0x63, 0x3D,
0x7C, 0x22, 0xC0, 0x9E, 0x1D, 0x43, 0xA1, 0xFF,
0x46, 0x18, 0xFA, 0xA4, 0x27, 0x79, 0x9B, 0xC5,
0x84, 0xDA, 0x38, 0x66, 0xE5, 0xBB, 0x59, 0x07,
0xDB, 0x85, 0x67, 0x39, 0xBA, 0xE4, 0x06, 0x58,
0x19, 0x47, 0xA5, 0xFB, 0x78, 0x26, 0xC4, 0x9A,
0x65, 0x3B, 0xD9, 0x87, 0x04, 0x5A, 0xB8, 0xE6,
0xA7, 0xF9, 0x1B, 0x45, 0xC6, 0x98, 0x7A, 0x24,
0xF8, 0xA6, 0x44, 0x1A, 0x99, 0xC7, 0x25, 0x7B,
0x3A, 0x64, 0x86, 0xD8, 0x5B, 0x05, 0xE7, 0xB9,
0x8C, 0xD2, 0x30, 0x6E, 0xED, 0xB3, 0x51, 0x0F,
0x4E, 0x10, 0xF2, 0xAC, 0x2F, 0x71, 0x93, 0xCD,
0x11, 0x4F, 0xAD, 0xF3, 0x70, 0x2E, 0xCC, 0x92,
0xD3, 0x8D, 0x6F, 0x31, 0xB2, 0xEC, 0x0E, 0x50,
0xAF, 0xF1, 0x13, 0x4D, 0xCE, 0x90, 0x72, 0x2C,
0x6D, 0x33, 0xD1, 0x8F, 0x0C, 0x52, 0xB0, 0xEE,
0x32, 0x6C, 0x8E, 0xD0, 0x53, 0x0D, 0xEF, 0xB1,
0xF0, 0xAE, 0x4C, 0x12, 0x91, 0xCF, 0x2D, 0x73,
0xCA, 0x94, 0x76, 0x28, 0xAB, 0xF5, 0x17, 0x49,
0x08, 0x56, 0xB4, 0xEA, 0x69, 0x37, 0xD5, 0x8B,
0x57, 0x09, 0xEB, 0xB5, 0x36, 0x68, 0x8A, 0xD4,
0x95, 0xCB, 0x29, 0x77, 0xF4, 0xAA, 0x48, 0x16,
0xE9, 0xB7, 0x55, 0x0B, 0x88, 0xD6, 0x34, 0x6A,
0x2B, 0x75, 0x97, 0xC9, 0x4A, 0x14, 0xF6, 0xA8,
0x74, 0x2A, 0xC8, 0x96, 0x15, 0x4B, 0xA9, 0xF7,
0xB6, 0xE8, 0x0A, 0x54, 0xD7, 0x89, 0x6B, 0x35
};
uint8_t calculate_crc(const uint8_t *data, size_t length) {
uint8_t crc = 0x00;
for (size_t i = 0; i < length; i++) {
#if 1
uint8_t idx = (uint8_t)(crc ^ data[i]);
crc = (crc >> 8) ^ crc_table[idx];
#else
uint8_t idx = (uint8_t)((crc >> 0) ^ data[i]);
crc = (crc << 8) ^ crc_table[idx];
#endif
}
return crc ^ 0x00;
}About CRC-8/MAXIM-DOW
CRC-8/MAXIM-DOW is a reflected 8-bit CRC commonly used by Dallas and Maxim one-wire devices.
CRC-8/MAXIM-DOW is a 8-bit CRC model defined by polynomial 0x31, an initial register value of 0x00, and final XOR 0x00. It processes reflected input bytes and reports a reflected output.
Documented application context for this model includes 1-Wire devices, Dallas sensors, Device identification. The calculator above applies this exact parameter set to the current input; the published Check value below is instead the fixed verification result for ASCII 123456789.
Model characteristics
A model is identified by its complete parameter set, not its polynomial alone.
- Bit order
- Reflected
- Register start
- 0x00
- Final XOR
- 0x00
- Published check
- 0xA1
Implementation checks for CRC-8/MAXIM-DOW
- Use a 8-bit register and polynomial 0x31.
- Initialize the register to 0x00 and use XorOut 0x00 exactly as listed; changing either value defines a different model.
- Verify the implementation with ASCII “123456789”; the expected result is 0xA1.
Continue with the main calculator, browse the algorithm catalog, compare models in the Algorithm Reference section, or generate a lookup table.
Complete CRC-8/MAXIM-DOW parameters
| Parameter | Value | Meaning | Reference |
|---|---|---|---|
| Width | 8 bits | CRC register and result width | Read guide |
| Poly | 0x31 | Generator polynomial without the leading term | Read guide |
| Init | 0x00 | Initial CRC register value | Read guide |
| RefIn | Yes | Reflect each input byte before processing | Read guide |
| RefOut | Yes | Reflect the register before XOR Out | Read guide |
| XorOut | 0x00 | Final value XORed with the CRC register | Read guide |
| Check | 0xA1 | CRC of ASCII “123456789” | Read guide |
| Residue | 0x00 | Expected residue after appending a valid CRC | Read guide |
AliasesCRC-8/MAXIMDALLAS CRC8DOW-CRC
Where CRC-8/MAXIM-DOW is used
- 011-Wire devices
- 02Dallas sensors
- 03Device identification
CRC-8/MAXIM-DOW FAQ
What is the check value for CRC-8/MAXIM-DOW?
For the standard ASCII test input 123456789, the check value of CRC-8/MAXIM-DOW is 0xA1.
What polynomial does CRC-8/MAXIM-DOW use?
CRC-8/MAXIM-DOW uses the 8-bit polynomial 0x31.
Does CRC-8/MAXIM-DOW use reflected input and output?
For CRC-8/MAXIM-DOW, RefIn is Yes and RefOut is Yes.
What is CRC-8/MAXIM-DOW commonly confused with?
CRC-8/NRSC-5 uses the same polynomial (0x31), which is the usual source of mix-ups — matching the polynomial alone does not reproduce CRC-8/MAXIM-DOW. The two models differ in initial value, input reflection, and output reflection, so a port from one to the other needs those fields checked explicitly, not just the poly.