ISP-IAP API Read CRC checksum ISP

Get the CRC checksum of a block of RAM or flash. CMD_SUCCESS followed by 8 bytes of CRC checksum in ASCII format.

The checksum is calculated as follows:

CRC-32 polynomial: x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1

Seed Value: 0xFFFF FFFF

No bit order reverse for data input

No 1’s complement for data input

No bit order reverse for CRC sum

No 1’s complement for CRC sum

Table 1. ISP-IAP API UART ISP Read CRC checksum command
Command S
Input Address: The data are read from this address for CRC checksum calculation. This address must be on a word boundary.

Number of Bytes: Number of bytes to be calculated for the CRC checksum; must be a multiple of 4.

Return Code CMD_SUCCESS followed by data in plain binary format

ADDR_ERROR (address not on word boundary) |


COUNT_ERROR (byte count is not a multiple of 4) |



Description This command is used to read the CRC checksum of a block of RAM or flash memory. This command is blocked when code read protection is enabled.
Example "S 268436736 4<CR><LF>" reads the CRC checksum for 4 bytes of data from address 0x1000 0500. If checksum value is 0xCBF43926, then the host will receive: "3421780262 <CR><LF>"