ISD3900
Publication Release Date: Dec 10, 2013
- 73 -
Revision 1.5
This command queries the ISD3900 device status. For details of device status see Section 12.2. If
device is powered up, the two status bytes will be repeated for each two dummy bytes sent to the SPI
interface. If device is powered down, only one status byte 80h shows up to the SPI interface at the
same time the command is sent. This command is always accepted.
13.2.2 Read Interrupt
READ_INT
Byte Sequence:
Host controller
0x46
0xXX
ISD3900
Status Byte
Interrupt Status Byte
Description:
Query device status and clear interrupt flags.
This command queries the ISD3900 device status and clears any pending interrupts. After this
command the hardware interrupt line will return inactive. The INT bit of the status register along with
any status error bits will return inactive.
This command is accepted whenever device is powered up.
13.2.3 Read Recorded Message Address Details
RD_MSG_ADD
Byte Sequence:
Host controller
0x42
X
X
X
X
X
ISD3900
STATUS0
A[23:16]
A[15:8]
A[7:0]
LEN[15:8]
LEN[7:0]
Description:
Reports the start sector address A/4096 of current message and length, LEN, in
4kByte sectors
This interrogates the status of the last or current audio record command. It returns the start address so
that the user can address a message for playback and also returns the number of sectors that the
message has used. It should be issued immediately after a record is initiated to correctly get retrieve
the message start address and current length of message. After a STOP command or overflow
condition, data is valid for final message length after CMD_BSY has returned low and before a
subsequent audio command is issued.