10.6 Get Memory CRC Command (HCI-ISDAP Opcode - 0x0114)

The HCI-ISDAP command allows the host MCU to command a 16-bit CRC calculation over a range of memory in the BM70/71 module, which is useful to the host MCU for verifying contents of memory after completing various HCI-ISDAP commands.

To properly use this command, the host MCU needs to understand the memory arrangement in the BM70/71 module. The BM70/71 module contains a Harvard memory architecture with segmented memory. The size of the bank/segments in the code and data space is 64 Kbytes. The programmer can use the memory type and memory sub-type parameters in this command to indicate the memory space where the CRC calculation must be performed. The host MCU uses the MSb, 16 bits of the address parameter value to identify one of the four memory bank/segments for code space or one of the two memory banks for data space, and the LSb, 16 bits to address a specific memory location with the selected memory bank/segment.

The calculation, which the host MCU can instruct the BM70/71 module to perform, uses an internal 16-bit H5 CRC error detection scheme to verify the integrity of a block of data in memory. The CRC calculates LSb first. The CRC is running on an 8-bit value read from memory. The following table provides details about the HCI-ISDAP command.