AN2282

Firmware

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2

Firmware

The firmware is developed in several layers following the standard ISO/OSI model for

networking from physical layer up to application layer. A firmware architecture diagram is

shown below in Figure 7.

Figure 7.

Firmware architecture

The firmware also includes a module for the configuration of the GPIO used to manage the

reset signal and interrupt signal of the Ethernet Controller.

2.1

Ethernet controller driver

The two lower layers (the Ethernet Device Driver layer and the STR7 Hardware Libraries

and Device Interface layer) manage the CS8900A Ethernet controller and the physical

access to the device.

2.1.1

Low Level Interface

The emi.c is part of the STR710 library and it defines the functions for configuration of the

EMI peripheral. The ethdrv.c module provides the interface function to the upper layer and is

useful for low level access to the Ethernet controller when it is accessed in I/O mode:

●

void outw(int address, short data);

Writes a 16-bit data word to an I/O

register located at a given address.

●

char inb(int address);

Reads a byte data from an I/O register located at a given

address.

●

short inw(int address);

Reads a 16-bit word from an I/O register located at a

given address.

The module also provides the function for hardware reset of the Ethernet controller:

●

void reset_NIC(void);

Buffer

Device Driver

Modules: ethdev.c

Ethernet Device Driver

Modules: lan8900.c

STR7 Hardware Libraries and Device Interface

Modules: emi.c, ethdrv.c

Application Layer

TCP/IP Layers

Modules: uip.c, uip_arp.c