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sbcp-uc/include/packet.h
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packet.h
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/*
File: tx_packet.h
Author: tuleu
Created on May 23, 2012, 10:13 AM
*/
#ifndef SBCP_TX_PACKET_H_
#define SBCP_TX_PACKET_H_
#include "sbcp-uc_config.h"
#include "buffers.h"
#include "sbcp.h"
/**
* \defgroup sbcp_packet_m SBCP Packet
*
* \brief Defines function to generate and manipulate response packet.
*
* These are intended to be used in sbcp_instruction_callback. To make a response
* packet one should :
*
* -# prepare the packet using sbcp_prepare_r_packet()
* -# insert the data if any inside the packet by either :
* - use *only* sbcp_put_reg_in_r_packet() if you are only sending back
* sbcp_registers. It will also efficiently compute the checksum of the
* packet, so no other calls are needed :).
* - diretcly manipulate the data :
* -# Access the data array using sbcp_r_packet_payload_buffer()
* -# Oncle all data i inserted, use sbcp_compute_packet_cs() to compute
* the checksum and place it inside
* sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS]]
* -# Mark that the response packet is ready, using sbcp_mark_r_packet_ready().
*
*
* \ingroup sbcp_m
*/
/**
* Returns the payload array of the response packet. If you put a register inside the
* packet, please prefer sbcp_put_reg_in_r_packet(), as it efficiently compute
* the checksum,
*/
#define sbcp_r_packet_payload_buffer (&(sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS]))
/**
* Prepares the feedback packet with the given size and error code.
* @param payload the sbcp_payload_size of the packet
* @param error the sbcp_error code of the packet.
*/
#define sbcp_prepare_r_packet(payload,error) do{\
sbcp_r_packet_buffer[SBCP_INSTRUCTION_POS] = (error);\
sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS] = (payload);\
sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + payload] = SBCP_MY_CLASS + SBCP_MY_ID + payload + error;\
}while(0)
/**
*
* @param buffer
* @return
*/
#define sbcp_put_reg_in_r_packet(payload_index,reg_addr)do{\
sbcp_r_packet_payload_buffer[payload_index ] = sbcp_reg_msb(reg_addr);\
sbcp_r_packet_payload_buffer[payload_index + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS]] += sbcp_reg_msb(reg_addr);\
sbcp_r_packet_payload_buffer[payload_index + 1] = sbcp_reg_lsb(reg_addr);\
sbcp_r_packet_payload_buffer[payload_index + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS]] += sbcp_reg_lsb(reg_addr);\
}while(0)
#ifdef SBCP_NO_BUFFER_ALLOCATION
#define sbcp_mark_r_packet_ready() do{\
/*finish the cs*/\
sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS] ] = ~(sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS] ]) & 0x00ff;\
/**\todo implement */\
}while(0)
#else
#define sbcp_mark_r_packet_ready() do{\
/*finish the cs*/\
sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS] ] = (sbcp_r_packet_buffer[SBCP_PAYLOAD_START_POS + sbcp_r_packet_buffer[SBCP_PAYLOAD_SIZE_POS] ]) & 0x00ff;\
sbcp_mark_tx_buffer_occupied();\
}while(0)
#endif
uint8_t sbcp_compute_packet_cs(unsigned int * buffer);
#endif // SBCP_TX_PACKET_H_
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