Embedded Software for SoC - Grupo de Mecatrônica EESC/USP

Chapter 24
SDRAM-ENERGY-AWARE MEMORY
ALLOCATION FOR DYNAMIC MULTI-MEDIA
APPLICATIONS ON MULTI-PROCESSOR
PLATFORMS
P. Marchal 1 , J. I. Gomez 2 , D. Bruni 3 , L. Benini 3 , L. Piñuel 2 , F. Catthoor 1 ,
and H. Corporaal 4
1 IMEC and K.U.Leuven-ESAT, Leuven, Belgium; 2 DACYA U.C.M.. Spain; 3 D.E.I.S. University
of Bologna, Italy; 4 IMEC and T.U. Eindhoven, Nederland
Abstract. Heterogeneous multi-processors platforms are an interesting option to satisfy the
computational performance of future multi-media applications. Energy-aware data management
is crucial to obtain reasonably low energy consumption on the platform. In this paper we show
that the assignment of data of dynamically created/deleted tasks to the shared main memory
has a large impact on platform’s energy consumption. We introduce two dynamic memory
allocators, which optimize the data assignment in the context of shared multi-banked memories.
Key words: fynamic multi-media applications, data-assignment, data locality, SDRAM, multiprocessor
1. INTRODUCTION
In the near future, the silicon market will be driven by low-cost, portable
consumer devices, which integrate multi-media and wireless technology.
Applications running on these devices require an enormous computational
performance (1–40GOPS) at low energy consumption (0.1–2W). Heterogeneous
multi-processor platforms potentially offer enough computational
performance. However, energy-aware memory management techniques are
indispensable to obtain sufficiently low energy consumption. In this paper, we
focus on the energy consumption of large off-chip multi-banked memories
(e.g. SDRAMs) used as main memory on the platform. They contribute
significantly to the system’s energy consumption [1]. Their energy consumption
depends largely on how data is assigned to the memory banks. Due to
the interaction of the user with the system, which data needs to be allocated
is only known at run-time. Therefore, fully design-time based solutions as
proposed earlier in the compiler and system synthesis cannot solve the problem
(see Section 4). Run-time memory management solutions as present in
nowadays operating systems are too inefficient in terms of cost optimization
(especially energy consumption). We present two SDRAM-energy-aware
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A Jerraya et al. (eds.), Embedded Software for SOC, 319–330, 2003.
© 2003 Kluwer Academic Publishers. Printed in the Netherlands.