Renesas R8A66597, Руководство пользователя

Страница: 12 / 59

Renesas USB Device USB Host Mass Storage Class Driver(HMSC)
R01AN0513EJ0110 Rev.1.10 Page 12 of 55
Aug 10, 2011
3. USB Mass Storage Class Driver (HMSCD)
3.1 Basic Functions
HMSCD is registered in HCD when the application (APL) starts the device driver. The functions of HMSCD are as
follows.
1. Verifying devices (determining if USB storage devices are ready to operate)
2. Communicating storage commands using the BOT protocol
3.2 Issuing Requests to HMSCD
The interface functions described below are used when accessing USB storage devices. In response to requests from a
higher layer, HMSCD sends notification of results by means of function return values.
3.3 Functions and Features
HMSCD comprises three layers: wrapper layer for HMSDD (DDI functions), wrapper layer for HCD (HCI functions),
and HMSCD itself. The DDI function is modified when HMSDD is changed, and the HCI function is modified when
HCD is changed. This can use Host mass storage class driver without changing it.HMSCD supports storage commands
necessary for accessing USB storage devices and sample storage commands.
HMSCD has the following features.
Support for USB mass storage class BOT.
Support for SFF-8070i (ATAPI) and SCSI USB mass storage subclasses.
Sharing of a single pipe for IN/OUT directions or multiple devices.
Sample device driver (HMSDD) provided.
Specific indication of interface (connection example) with FAT file system library.
Specific indication of interface (connection example) with HCD of USB-BASIC-F/W.
3.4 Pipe Information Table
Table 3.1 lists details of the HMSCD pipe information table.
Table 3.1 Pipe Information Table
Register PIPE1 (receive pipe setting) PIPE1 (transmit pipe setting)
1 PIPECFG BFRE = 0, DBLB = 1, SHTNAK = 1
Settings other than the above obtained
from descriptor. BFRE = 0, DBLB = 1,
Settings other than the above obtained from
descriptor.
2 PIPEMAX None (Obtained from descriptor.) None (Obtained from descriptor.)
3 PIPEPERI None None
4 FIFOPORT CPU access to CFIFO CPU access to CFIFO