ISD3900
Publication Release Date: Dec 10, 2013
- 74 -
Revision 1.5
13.2.4 Read Message Length
RD_MSG_LEN
Byte Sequence:
Host controller
0x44
0xXX
0xXX
ISD3900
Status Byte
LEN[15:8]
LEN[7:0]
Description:
Read number of sectors played by current PLAY command.
This command returns the number of sectors played by the current PLAY_MSG@ command, or
recorded by the current REC_MSG command. This command is used to determine the offset position
of the currently playing/recording message. It can be used to resume the playback of a message at a
particular sector. For instance, if a PLAY_MSG(SA, 0) command was sent to start playback of a
message from SA then a STOP was sent during playback of the third sector of the message, then
RD_MSG_LEN would return LEN=3. A subsequent PLAY_MSG(SA,2) command would restart the
playback from the beginning of the sector where playback was stopped, that is send PLAY_MSG(SA,
LEN-1). Now, if a STOP was issued after an additional three sectors of playback (message is now
playing the sixth sector), RD_MSG_LEN would return LEN=6.
13.2.5 Read I3900 ID
READ_ID
Byte
Sequence:
Host controller
0x48
0xXX
0xXX
0xXX
0xXX
ISD3900
Status Byte PART_ID MAN_ID
MEM_TYPE DEV_ID
Description:
Return memory ID of external memory
This command queries the ISD3900 to returns four bytes to indicate the I3900 family member and the
manufacturer, size and type of external memory of the device. The four bytes returned are:
PART_ID
– Identifies which 3900 family member.
MAN_ID
– Manufacturer ID, which is 0xEF for Winbond.
MEM_TYPE
– Memory type, which is 0x30.
DEV_ID
– Device ID indicates the memory size as the table below.
Capacity
Value
4Mb
13
8Mb
14
16Mb
15
32Mb
16
64Mb
17