X-Git-Url: http://cloudbase.mooo.com/gitweb/z180-stamp.git/blobdiff_plain/3531528ecedde37d5ebc67a330d192565290175a..05437fb4cdb907816a4fc3ffafa2617fcf33266a:/fatfs/doc/en/dread.html diff --git a/fatfs/doc/en/dread.html b/fatfs/doc/en/dread.html index f81cf90..2e7c279 100644 --- a/fatfs/doc/en/dread.html +++ b/fatfs/doc/en/dread.html @@ -32,9 +32,9 @@ DRESULT disk_read (
buff
Pointer to the byte array to store the read data.
sector
-
Start sector number in logical block address (LBA).
+
Start sector number in 32-bit LBA.
count
-
Number of sectors to read. FatFs specifis it in range of from 1 to 128.
+
Number of sectors to read in range of from 1 to 128..
@@ -56,9 +56,10 @@ DRESULT disk_read (

Description

-

The memory address specified by buff is not that always aligned to word boundary because the type of argument is defined as BYTE*. The misaligned read/write request can occure at direct transfer. If the bus architecture, especially DMA controller, does not allow misaligned memory access, it should be solved in this function. There are some workarounds described below to avoid this issue.

+

The data read/write operation to the storage devices is done in unit of sector. FatFs supports the sector size in range of from 512 to 4096 bytes. When FatFs is configured to fixed sector size (_MIN_SS == MAX_SS, this will be the most case), the read/write function must work at that sector size. If variable sector size is selected (_MIN_SS < MAX_SS), FatFs inquires the sector size with disk_ioctl() after initialization. +

The memory address specified by buff is not that always aligned to word boundary because the argument is defined as BYTE*. The misaligned read/write request can occure at direct transfer. If the bus architecture, especially DMA controller, does not allow misaligned memory access, it should be solved in this function. There are some workarounds described below to avoid this issue.