Zilog EZ80F91AZA Manual do Utilizador descarregar pdf (Página 23)

UM017914-1211 Integrating a Flash Driver

Zilog File System

User Manual

Integrating a Flash Driver

This chapter briefly describes how to create a new driver for a Flash device other than

those supported, and how to integrate this Flash driver with the Zilog File System library

so that files and data can be stored in the Flash driver within the structure of the Zilog File

System.

The Zilog File System’s hardware abstraction module requires the Flash driver to be writ-

ten with an appropriate prototype and requires the function to return particular values

when the function succeeds or fails.

The Zilog File System requires the Flash driver to provide basic access routines for Flash

that perform the reading or writing of a number of bytes to and from Flash memory, in

addition to performing the erasure of the physical blocks of Flash. For more information

about the functionality of the basic access routines of the Flash driver that must be inte-

grated with the Zilog File System, refer to Flash Driver APIs section in the Zilog Real-

Time Kernel Reference Manual (RM0006).

Depending upon the characteristics of the Flash device

, access to the Flash device can be

made sequentially and on a first-come/first-served basis. To achieve this type of sequence,

the developer must use any one of the synchronization objects present in RZK (for exam-

ple, a semaphore). These functions are referred to as Flash driver wrapper functions in the

Zilog File System.

When the Flash driver wrapper functions and driver routines are ready, the Flash driver is

integrated with the Zilog File System to store files and directories in Flash memory. The

Zilog File System provides a way of integrating a custom Flash driver that can be used to

store files and directories.

The

ZFS_Conf.c file defines a global variable, g_zfs_cfg, which is of the

ZFS_CONFIG_t structure type. You can change the member values of the structure to suit

your requirements. For more information about Zilog File System configuration, see

<CrossRef>Zilog File System Configuration on page 8. For more information about creat-

ing a project workspace for your sample application, refer to Zilog Real-Time Kernel User

Manual (UM0075).

To provide an example, suppose a custom Flash driver, with the name

MYFLASH, has rou-

tines such as

MYFLASH_Init, MYFLASH_Read, MYFLASH_Write, MYFLASH_Erase and

MYFLASH_Close and that the starting address is 0x100000, with seven erasing blocks to

be used for the storage of files and directories for the Zilog File System. Each block con-

tains 64 KB of space of storage. The configuration block must appear like the code seg-

ment provided below:

1. Some Flash devices, upon reading a byte, return the status byte if the Flash device is currently operating in write or erase modes.

1 2 ... 18 19 20 21 22 23 24 25 26

Comentários a estes Manuais

Sem comentários

Zilog EZ80F91AZA Manual do Utilizador Página 23

Comentários a estes Manuais

Manuais e produtos relacionados com Sensores Zilog EZ80F91AZA