Context :

Aims : With the purpose of producing the first detailed full view of Puppis A in X-rays , we carried out new XMM-Newton observations covering the missing regions in the southern half of the supernova remnant ( SNR ) and combined them with existing XMM-Newton and Chandra data .

Methods : Two pointings toward the south and southwest of Puppis A were observed with XMM-Newton .
We combined these data with archival XMM-Newton and Chandra data and produced images in the 0.3-0.7 , 0.7-1.0 and 1.0-8.0 energy bands .

Results : We present the first sensitive complete X-ray image of Puppis A .
We investigated its morphology in detail , carried out a multiwavelength analysis and estimated the flux density and luminosity of the whole SNR .
The complex structure observed across the remnant confirms that Puppis A evolves in an inhomogeneous , probably knotty interstellar medium .
The southwestern corner includes filaments that perfectly correlate with radio features suggested to be associated with shock/cloud interaction .
In the northern half of Puppis A the comparison with Spitzer infrared images shows an excellent correspondence between X-rays and 24 and 70 \mu m emission features , while to the south there are some matched and other unmatched features .
X-ray flux densities of 12.6 \times 10 ^ { -9 } , 6.2 \times 10 ^ { -9 } , and 2.8 \times 10 ^ { -9 } erg cm ^ { -2 } s ^ { -1 } were derived for the 0.3-0.7 , 0.7-1.0 and 1.0-8.0 keV bands , respectively .
At the assumed distance of 2.2 kpc , the total X-ray luminosity between 0.3 and 8.0 keV is 1.2 \times 10 ^ { 37 } erg s ^ { -1 } .
We also collected and updated the broad-band data of Puppis A between radio and GeV \gamma -ray range , producing its spectral energy distribution .
To provide constraints to the high-energy emission models , we re-analyzed radio data , estimating the energy content in accelerated particles to be \mathrm { U _ { min } } = 4.8 \times 10 ^ { 49 } erg and the magnetic field strength \mathrm { B } \sim 26 \mu G .

Conclusions :