Rohm BU9458KV, Примечание к применению

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BU9458KV Application Note Rev. 0.02
PROPRIETARY AND CONFIDENTIAL - 28/42-
2009/05/28
V.2.8.2 Power ON sequence
The operations from power ON to TOC/initial setting during execution of resume play have the completely same flow as
for normal play.
V.2.8.3 Check memory device
The LSI checks whether the inserted and recognized memory device is the same one when obtaining the resume data.
After the power ON sequence is completed, the LSI reads the status and checks whether the device is the same.
Check the MDEVUSB status and MDEVSD status
If the selected memory device is the other one, send the CHMG_DEV command to change the device.
V.2.8.4 TOC/initial setting
The TOC/initial setting operation has the same flow as for normal play.
V.2.8.5 Resume play initial setting
During resume play, set the resume initial settings such as volume setting for resume play and audio output format in
the completed initial setting condition. Use the statuses read in V.2.8.1 for the resume initial setting.
Perform the following initial setting only and do not execute REPEAT/RANDOM play settings.
(1) Volume setting
(2) EQ setting (only when the line output is selected for audio output)
(3) Digital audio output setting (only when digital audio output is selected for audio output)
V.2.8.6 Send SET_RESUME_INFO command and start resume play
Send 42-Byte resume data obtained from the read status command, READ_RESUME_INFO, by every 6 Bytes.
SET_RESUME_INFO command
To transfer 42-Byte data by every 6 Bytes, the SET_RESUME_INFO command is executed 7 times in all.
After 42-Byte SET_RESUME INFO commands have been sent, and the last one, SET_RESUME_INFO7 command has
been sent, the LSI automatically searches resume files.
During search, if the LSI cannot search a MP3 file for resume play because of change or no insertion of the memory
device, it issues an error occurrence in the STATUS5:RES_ERR status. Therefore, when sending a
SET_RESUME_INFO command, be sure to read the STATUS5:RES_ERR status and check for errors. If an error
occurs, the LSI automatically plays the first tune in the memory device. A resume error may possibly arise in the
following cases:
(1) When the file number or folder number does not match
1st Byte 2nd Byte
0x53
Setting value
SET_VOL
1st Byte 2nd Byte 3rd Byte 4th Byte
0x51
0x20
SET_DOUT
Select output format
1st Byte 2nd Byte
0x51 0x4 X
SET_RESUME
_INFO X
6 Byte Write
1st Byte 2nd Byte
0x5E 0x01
READ_BUFF 1 Byte Read
1st Byte 2nd Byte
0x50 0x08
CHNG_DEV
1st Byte 2nd Byte
0x52
Select
SET_EQ