ISD3900
Publication Release Date: Dec 10, 2013
- 34 -
Revision 1.5
11
INITIALIZATION & RECORD/PLAY FLOWCHART
Whenever the ISD3900 detect as power-on reset condition or a high on the RESET pin of the device it
begins a power-on initialization (POI) sequence. Whenever the ISD3900 receives a power up
command (PU) when it is in a power down state, it begins a power-up initialization (PU) sequence.
Voice Macros VM(0) and VM(1) are reserved for POI and PU initialization routines. If no reserved
memory exists or if the vectors VM(0) or VM(1) are not set, then a default routine is executed. The
default sequence for POI is to power-down the ISD3900. The default PU sequence is to select a clock
configuration of internal oscillator with PLL active for Fs=32kHz.
POI
VP Sector
Exist
Send PU to
Memory
Send PD to
memory
VM(0)?
yes
yes
no
no
Execute VM(0)
IDLE
PD
PU
VP Sector
Exist
Send PU to
Memory
Assert
PU_RDY
VM(1)?
yes
yes
no
no
Execute VM(1)
IDLE
Set Defaul
CLK_CFG
(0x34)
Figure 11-1 POI and PU Initialization Flowcharts
