SMC Networks LH79520 SoC ARM720T, ARM720T_LH79520 manual Configuring the Processor

ARM720T_LH79520 – Sharp LH79520 SoC with ARM720T 32-bit RISC Processor

Name	Type	Polarity/Bus size	Description
PER_RESET	I	Low	Reset signal from the LH79520.
ARM7_SYS_RESE	O	Low	Reset signal to the LH79520 (internally connected from the RST_I
T			line).
PER_CLK	I	Rise	Clock signal from the LH79520
ARM7_SYS_CLK	O	Rise	External Clock signal to the LH79520 (internally connected from the
			CLK_I line).
PER_READY	O	Low	Static Memory Controller External Wait Control
PER_INT	O	5/High	External Interrupt lines. These lines appear as interrupts 0 to 4 when
			handled by the physical device's Vectored Interrupt Controller (see
			Interrupts).

Configuring the Processor

The architecture of the ARM720T_LH79520 can be configured after placement on the schematic sheet, or OpenBus System document, using the Configure (32-bit Processors) dialog (Figure 2). Access to this dialog depends on the document in which you are working:

•In the Schematic document – simply right-click over the device and choose the command to configure the processor from the context menu that appears. Alternatively, click on the Configure button, available in the Component Properties dialog for the device.

•In the OpenBus System document – access the dialog by right-clicking over the component and choosing the command to configure the processor from the menu that appears. Alternatively, double-click on the component to access the dialog directly.

Figure 2. Options to configure the architecture of the ARM720T_LH79520.

The drop-down field at the top-right of the dialog enables you to choose the type of processor you want to work with. As the pinouts for the Wishbone interfaces between the 32-bit processors are the same, you can easily change the processor used in your design without having to extensively rewire the external interfaces.

As you select the processor type, the Configure (32-bit Processors) dialog will change accordingly to reflect the architectural options available. The symbol on the schematic will also change to reflect the type of processor and configuration options chosen.

For the ARM720T_LH79520, a single architectural option is available that allows you to define the size of the internal memory for the processor. This memory, also referred to as ‘Low’ or ‘Boot’ memory is implemented using true dual port FPGA Block RAM and will contain the boot part of a software application and the interrupt and exception handlers.

8 CR0162 (v2.0) March 10, 2008