3.4.1 Read Buffer Size

For the purposes of programming, this HCI command packet is used:

1. To make sure the BM70/71 is functioning and ready for programming; a valid HCI Event packet response indicates this.
2. To discover the number of bytes of data that can be sent to the BM70/71 device in an HCI command or HCI-ISDAP Flash command.

For the external programmer or host, this command effectively provides the size of the internal buffer available in the BM70/71, which is used for receiving packets. The host must not send any HCI command packet or HCI-ISDAP command packet greater in total length than the value returned by the BM70/71 from this command. Not obeying this buffer size limitation will result in undefined device operation. When starting a programming flow, Microchip recommends that the programmer send this HCI command packet as the first message sent to the BM70/71.