ISD3900
Publication Release Date: Dec 10, 2013
- 78 -
Revision 1.5
This command powers up the device. If device already powered up this command has no effect. If
powered down, then the internal power up sequence is initiated. If the PU voice macro is present this
is executed, otherwise the device defaults to power up the internal oscillator. When power up is
complete the PD bit of the status register will go low and the RDY bit high. Until this event no other
commands will be accepted by the ISD3900.
A formal power-up procedure is as follows:
Send PWR_UP command.
Poll Status until bit-6 DBUF_RDY goes high, which means ready.
Poll Status until bit-2 VM_BSY goes low, which means voice macro 1 finishes.
13.4.2 PWR_DN
– Power Down
PWR_DN
Byte Sequence:
Host controller
0x12
ISD3900
Status
…
Description:
Powers down the device after any active commands finish
This command powers down the device. If the device is currently executing a command the device will
powers down when the command finishes. If sent while recording without a STOP command sent first
then device will record until full then power down. If playing or executing a voice macro, device will
power down after playback is finished. The PWR_DN command will not generate an interrupt.
PWR_DN has executed when PD bit of status goes high.
13.4.3 SET_CLK_CFG
– Set Clock Configuration Register
This sets the clock configuration register. The part reconfigures the clock and PLL configuration and
waits for stable clock conditions before accepting new commands. When the configuration is changed,
CMD_BSY will go high until clock configuration is complete. No new commands should be sent until
the device status shows device not busy. This command does not generate an interrupt.
SET_CLK_CFG
Byte Sequence:
Host
controller
0xB4
CFG_CLK[7:0]
ISD3900
Status Byte
Status Byte
Description:
Loads clock configuration register.