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#      flash_am29xxxxx_v2.cdl

#

#      Device driver for AMD am29xxxxx flash chips and compatibles

#

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######DESCRIPTIONBEGIN####

#

# Author(s):      bartv

# Contributors:

# Date:           2004-11-05

#

#####DESCRIPTIONEND####

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cdl_package CYGPKG_DEVS_FLASH_AMD_AM29XXXXX_V2 {

    display     "AMD am29xxxxx flash memory support"

    doc         ref/devs-flash-am29xxxxx.html

    parent      CYGPKG_IO_FLASH

    active_if   CYGPKG_IO_FLASH

    implements  CYGHWR_IO_FLASH_DEVICE

    include_dir cyg/io

    compile     am29xxxxx.c

    description "

        Flash memory support for AMD AM29xxxxx devices and compatibles.

        This driver implements the V2 flash driver API"

    cdl_option CYGNUM_DEVS_FLASH_AMD_AM29XXXXX_V2_PROGRAM_TIMEOUT {

        display         "Maximum number of iterations during a write"

        flavor          data

        default_value   100000000

        legal_values    1024 to 0x7fffffff

        description "

            Flash program operations may take a long time, and the driver

            needs to poll the device to detect when the operation has

            completed. This option controls the maximum number of iterations

            of the polling loop, before the driver will give up. The timeout

            should never actually trigger, as long as the hardware is

            functioning correctly. If a timeout does occur the flash device

            may be left in an inconsistent state. If very slow flash devices

            are used then the platform HAL may require a larger timeout."

    }

    cdl_option CYGNUM_DEVS_FLASH_AMD_AM29XXXXX_V2_PROGRAM_DELAY {

        display         "Delay between words while programming"

        flavor          data

        default_value   0

        legal_values    0 to 0x7fffffff

        description "The timings of certain processors and flash devices mean that

                     a short delay may be required between each word as it is programmed.

                     This option defines that delay in terms of iterations of a delay

                     loop."

    }

    cdl_option CYGNUM_DEVS_FLASH_AMD_AM29XXXXX_V2_ERASE_TIMEOUT {

        display         "Maximum number of iterations during a block erase"

        flavor          data

        default_value   100000000

        legal_values    1024 to 0x7fffffff

        description "

            The driver needs to poll the flash device during a block erase

            to detect when the operation has completed. This option controls

            the maximum number of iterations of the polling loop, before the

            driver will give up. The timeout should never actually trigger,

            as long as the hardware is functioning correctly. If a timeout

            does occur the flash device may be left in an inconsistent state.

            If very slow flash devices are used then the platform HAL may

            require a larger timeout."

    }

    cdl_option CYGIMP_DEVS_FLASH_AMD_AM29XXXXX_V2_LEAVE_INTERRUPTS_ENABLED {

        display         "Leave interrupts enabled during flash operations"

        active_if       { ! CYGHWR_DEVS_FLASH_AMD_AM29XXXXX_V2_CACHED_ONLY }

        default_value   0

        description "

            On typical hardware erasing or programming a flash block requires

            disabling interrupts and possibly the cache. During these operations

            some or all of the flash hardware will be unusable, and disabling

            interrupts is the only reliable way of ensuring that no interrupt

            handler or other thread will try to access the flash in the middle

            of the operation. This can have a major impact on the real-time

            responsiveness of typical applications.

            In some circumstances it is possible to leave interrupts enabled.

            The application must run in RAM, not in flash. There must be some

            way of accessing the flash which bypasses the cache. The application

            must only access the flash using the proper API, for example

            cyg_flash_read(), which ensures that only one thread at a time can

            access a flash device. Finally there must be no possibility of

            entering a ROM monitor running in flash. This can happen if RedBoot

            is used as the ROM monitor and virtual vectors are enabled. It can

            also happen when debugging the application via RedBoot or gdb stubs.

            If the application can absolutely guarantee that the flash will not be

            accessed during a flash operation then it is possible to enable this option,

            improving interrupt latency. Any unexpected flash accesses are likely

            to cause a system crash. If in doubt leave this option disabled."

    }

    cdl_interface CYGHWR_DEVS_FLASH_AMD_AM29XXXXX_V2_CACHED_ONLY {

        display         "Flash memory accesses are always cached"

        flavor          bool

        description "

            Flash memory devices are usually accessed via the cache to achieve

            acceptable performance. However erase and program operations need

            to access the flash directly, bypassing the cache. On some targets

            it is possible to access the flash in an uncached part of the

            address space, for example by suitable MMU settings. On other

            targets it is necessary to disable the cache while erasing or

            programming blocks of flash. In the latter case the platform HAL

            will implement this interface."

    }

    cdl_interface CYGHWR_DEVS_FLASH_AMD_AM29XXXXX_V2_CFI_BOGOSITY {

        display         "Include support for unusual CFI implementation"

        flavor          bool

        description "

          CFI, Common Flash Interface, is a standard allowing device drivers

          to query the hardware for characteristics such as the erase region

          layout. Some flash chips have a somewhat strange implementation of CFI,

          requiring extra code within the device driver. If CFI is used for device

          initialization and if the platform may come with one of these flash chips

          then the platform HAL will implement this interface."

    }

    cdl_interface CYGHWR_DEVS_FLASH_AMD_AM29XXXXX_V2_RESET_NEEDS_RESUME {

        display         "Erase/program resume is needed after reset"

        flavor          bool

        description "

           With true AMD-compatible flash parts, a reset command will also

           abort any suspended erase or program operations. But on some

           parts which are nearly but not quite compatible, such as AT49xxxxx,

           this does not happen, and so an erase/program resume command is

           needed after a soft reset in order to be able to use the chip."

    }

    cdl_option CYGNUM_DEVS_FLASH_AMD_AM29XXXXX_V2_ERASE_REGIONS {

        display         "Number of different erase regions"

        flavor          data

        default_value   4

        legal_values    1 to 64

        description "

            Flash devices vary widely in the way the various flash blocks are

            laid out. In uniform devices all flash blocks are the same size,

            for example 64 blocks of 64K each. Other devices have a boot block,

            where one of the big blocks is subdivided into a number of smaller

            ones. For example there could be a 16K block, followed by two 8K blocks,

            then a 32K block, and finally 63 64K blocks. Each sequence of blocks

            of a given size is known as an erase region, so a uniform device has

            a single erase region and the above boot block device has four

            erase regions. The driver needs to know the maximum number of erase

            regions that may be present, especially if CFI is used to determine

            the block details at run-time. Typically this option is controlled

            by a requires property in the platform HAL, so users do not need

            to edit it."

    }

    cdl_component CYGPKG_DEVS_FLASH_AMD_AM29XXXXX_V2_OPTIONS {

        display "AMD AM29xxxxx driver build options"

        flavor  none

        description   "

            Package specific build options including control over

            compiler flags used only in building the AMD am29xxxxx

            flash driver, and details of which tests are built."

        cdl_option CYGPKG_DEVS_FLASH_AMD_AM29XXXXX_V2_CFLAGS_ADD {

            display "Additional compiler flags"

            flavor  data

            no_define

            default_value { "" }

            description   "

                This option modifies the set of compiler flags for

                building the AMD am29xxxxx flash driver. These flags

                are used in addition to the set of global flags."

        }

        cdl_option CYGPKG_DEVS_FLASH_AMD_AM29XXXXX_V2_CFLAGS_REMOVE {

            display "Suppressed compiler flags"

            flavor  data

            no_define

            default_value { "" }

            description   "

                This option modifies the set of compiler flags for

                building the AMD am29xxxxx flash driver. These flags

                are removed from the set of global flags if present."

        }

    }

}