Embedded Software for SoC - Grupo de Mecatrônica EESC/USP

Introduction to Hardware Abstraction Layers for SOC 183
concurrently considering that it is a contract between SW and HW designers.
The SW is designed using the HAL API without considering the details of
HAL API implementation. Since the SW design can start as soon as the HAL
API is defined, SW and HW design can be performed concurrently thereby
reducing the design cycle.
To understand better SW reuse by HAL usage, we will explain the correspondence
between SW and HW reuse. Figure 14-4 exemplifies HW reuse.
As shown in the figure, to reuse a HW IP that has been used before in a SoC
design, we make it ready for reuse by designing its interface conforming to
a HW interface standard (in Figure 14-4(a)), i.e. on-chip bus interface standards
(e.g. VCI, OCP-IP, AMBA, STBus, CoreConnect, etc.). Then, we reuse
it in a new SoC design (Figure 14-4(b)).
Figure 14-5 shows the case of SW reuse. Figure 14-5(a) shows that a SW
IP, MPEG4 code, is designed for a SoC design #1. The SoC design uses a
HAL API (shaded rectangle in the figure). The SW IP is designed using the