ISD3900
Publication Release Date: Dec 10, 2013
- 77 -
Revision 1.5
13.3.4 Chip Erase
CHIP_ERASE
Byte Sequence:
Host controller
0x26
0x01
ISD3900
Status Byte
Status Byte
Description:
Initiate a mass erase of memory.
Interrupt
Generation:
CMD_ERR if device is busy and cannot accept command. CMD_FIN when
erase operation complete.
This erases the entire contents of the external memory.
The command will be accepted if status bits PD=0, DBUF_RDY=1, VM_BSY=0, CBUF_FUL=0 and
CMD_BSY=0. If any of these conditions are not met then a CMD_ERR interrupt will be generated and
the command ignored. If memory is mass erase protected an ADDR_ERR interrupt is generated.
Upon completion of erase a CMD_FIN interrupt is generated.
While the device is erasing no other commands will execute. If a PLAY or REC is sent it is queued in
the command buffer and will not execute until the erase is finished. If a DIG_RD or DIG_WR command
is sent to the device, RDY/BSYB pin will hold off any data transfer until the CHIP_ERASE has
completed.
When CHIP_ERASE is in progress, the Status bit 0 CMD_BSY goes high. Users could poll the status
to see if the erasing is done.
13.4
D
EVICE
C
ONFIGURATION
C
OMMANDS
.
This section describes 6 commands used to configure the ISD3900. These commands are used to:
Set up the clocking regime of the device including clock source and setting the master sample rate.
Configure the audio signal path.
Configure the compression and sample rate for message recording.
The signal path, compression and sample rate configuration are controlled by forty-eight bytes of
configuration register. These forty-eight bytes can be written individually or in a continuous sequential
manner. These configuration registers are double buffered such that a new configuration can be
loaded and only set active when the user desires.
13.4.1 PWR_UP
– Power up
PWR_UP
Byte Sequence:
Host controller
0x10
ISD3900
Status
…
Description:
Powers up device and initiates the power up sequence.