Architecture

UM0541

4/19

1

Architecture

1.1

DCP monitor

DCP monitor consists of the following files:

●

DCP.c - contains all functions of the DCP monitor

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DCP.h - header file used to configure the DCP monitor

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DCPPort_xxx.c - contains all functions specific for the target

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DCPPort_xxx.h - header file for DCPPort_xxx.c

All these files have to be included in the target side project to implement the DCP monitor.

1.1.1

DCP protocol

DCP protocol is used by CPU commander during a UART communication.

Figure 1 describes the format of a DCP frame.

Figure 1.

Serial communication frame format

FrameID (Frame Identifier): is used only if acknowledge management is set. It is a counter 8

bits long and identifies the frame.

Command ID (Command Identifier): is the identifier of the frame and is 32 bits long.

SYS (System) flag: when it is set, the frame is a system frame.

CRC (Cyclic Redundancy Check) flag: when it is set the CRC is present in the frame

otherwise not.

ACK (Acknowledge) flag: when it is set, the receiver must send an acknowledge frame.

Length: this field is 8 bits long and indicates the length of the data in bytes (from 0 to 255

bytes) present in the current frame.

Data: it contains from 0 up to 255 bytes of data.

CRC: if CRC flag is set the last filed contains the CRC value. It is 16 bits long.

CommandID

Length

Data

CRC

32 bits

8 bits

8 bits

0 - 255 bits

16 bits

FrameID

8 bits