MEMORY_CS(4)						     Kernel Interfaces Manual						      MEMORY_CS(4)

NAME

       memory_cs - MTD-aware PCMCIA memory card driver

SYNOPSIS

       insmod memory_cs.o [pc_debug=n] [mem_speed=n] [word_width=n] [force_size=n]

DESCRIPTION

       Memory_cs  is  the  Card Services driver for PCMCIA memory cards, and also provides direct memory access for other types of cards.  It pro-
       vides character-mode and block-mode for accessing any card's attribute and common memory address spaces, analogous to /dev/mem.	 Memory_cs
       will  allocate  a  free major device number when it is loaded.  It provides two types of minor devices: "direct" character-mode devices for
       raw access a card's entire PCMCIA common and attribute memory spaces, and "indirect" devices for accessing specific memory  partitions  via
       an appropriate Memory Technology Driver.  The bitwise layout of minor device numbers is one memory device.  'x' is set if this is a direct-
       access device, 'a' is set for attribute memory, and 'rr' is the region number (for indirect devices).  When memory_cs is bound to  a  card,
       it will report its major and minor device numbers to cardmgr(8).

       The  default  memory  card  initialization  script creates character special device files for the direct common memory and attribute memory
       devices.  It also creates character special devices for accessing the first attribute and common memory partitions, and a block device  for
       accessing the first common memory partition.  These devices have the following names:

       /dev/mem#c
	      Common memory direct access, character special device.

       /dev/mem#a
	      Attribute memory direct access, character special device.

       /dev/mem#c0c
	      Common memory region 0, character special device.

       /dev/mem#c0b
	      Common memory region 0, block special device.

       /dev/mem#a0c
	      Attribute memory region 0, character special device.

       The block special device for a card's common memory can be used to create a filesystem on a card, and the device can be mounted in much the
       same way as a floppy disk.  In some cases, you may need to explicitly specify the card's capacity when creating a filesystem.

       The character special devices can be used to read and write arbitrary numbers of bytes to arbitrary locations.  For devices that need to be
       explicitly  erased before writing, if a write request is aligned and sized on erase block boundaries for the target memory card, the driver
       will erase the target region before writing to the card.

       Since any PCMCIA card can be accessed as a memory card, memory_cs can be bound to any card regardless of function, and regardless  of  what
       other  drivers might also be bound to that card.  For example, this driver can be bound to a card and then used to read out the contents of
       the card's attribute memory.

PARAMETERS

       pc_debug=n
	      Selects the PCMCIA debugging level.  This parameter is only available if the module is compiled with debugging enabled.  A  non-zero
	      value enables debugging.

       mem_speed=n
	      Sets  the access speed of the shared memory window for direct access devices, in nanoseconds.  The default is 0 (i.e., no extra wait
	      states).	Values of up to 1000 are legal.

       word_width=n
	      A flag indicating if direct access devices should be configured for 8-bit (if 0) or 16-bit (if  1)  transfers.   The  default  is  1
	      (16-bit).

       force_size=n
	      Explicitly specifies the size of a simple SRAM card, skipping the default (and sometimes unreliable) size check.

IOCTLS

       These are defined in <pcmcia/memory.h>.

       MEMGETINFO
	      This takes an argument of type (region_info_t *), defined in <pcmcia/bulkmem.h>.	The structure will be filled in with memory region
	      information for  this device, such as access speed, erase block size, and JEDEC identifiers.

       MEMERASE
	      This takes an argument of type (erase_info_t *), specifying the offset and length of a memory region to be erased.

AUTHOR

       David Hinds - dahinds@users.sourceforge.net

SEE ALSO

       cardmgr(8), pcmcia(5), memory_cb(4).

pcmcia-cs							2000/06/12 21:24:48						      MEMORY_CS(4)