ISD3900
Publication Release Date: Dec 10, 2013
- 37 -
Revision 1.5
Table 12-4 Clock PLL N Divisor
CLK_N_DIV
CLK_N_DIV[1:0]
N
00
PLL_BYPASS
01
8
10
16
11
32
Table 12-5 External Clock Output
EXT Clock
CLK_OUT[1:0]
00
NONE
– OFF
01
Fosc
10
PLL_REF_CLK
11
MCLK
12.2
D
EVICE
S
TATUS
R
EGISTER
Whenever the ISD3900 receives an SPI command it also returns its current status via MISO. The
details of the status byte are shown below. For commands that are not reading digital data from the
device this status byte is sent via MISO for every byte of data sent to the ISD3900.
Table 12-6 Status Register Description
Status Byte
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
PD
DBUF_RDY
INT
RM_FUL
-
VM_BSY
CBUF_FUL
CMD_BSY
The individual bits of the status register refer to the following conditions:
PD
– If this bit is high then the device is powered down. The DBUF_RDY bit will be low, but all
device output pins will be high impedance. When PD is high only the READ_STATUS,
READ_INT and PWR_UP commands are accepted. If any other command is sent, it is ignored
and no interrupt for an error is generated.
DBUF_RDY
– in PD this bit is low indicating the device can only accept a PWR_UP (power
up) command. When PD is low this bit reflects the state of the RDY/BSY pin.
INT
– an interrupt has been generated. The interrupt is cleared by the READ_INT command.
Interrupt type can be determined by the bits of the Interrupt Status Byte.
RM_FUL
– Recording Memory is full. This bit will be set if a record command fills the memory.
This bit is reset by an ERASE_MSG@, ERASE_MEM, or CHIP_ERASE operation.
VM_BSY
– indicates the device is processing a voice macro. The device will not respond to a