AK7746 Datasheet, PDF (52/62 Pages) Asahi Kasei Microsystems – Audio DSP with 5-channel 24-bit ADC and Input Mux

[ASAHI KASEI]
[AK7746]
3) Write during RUN phase
a) CRAM rewrites preparation and writes (during RUN phase)
This function is used to rewrite CRAM (coefficient RAM) during program execution. After inputting the command code,
you can input a maximum of 16 data (2 bytes 1set) of a continuous address you want to rewrite, then input the write command code and
rewrite the leading address. Every time the RAM address to be rewritten is specified, the contents of RAM are rewritten. The
following is an example to show how five data bytes from address "10" of the coefficient RAM are rewritten:
Coefficient RAM execution address
7 8 9 10 11 13 16 11 12 13 14 15
ÈÈ
ÈÈÈ
Rewrite position
} }Ç
} }}
Note that address "13" is not executed until address "12" is rewritten.
Data transfer procedure
* Preparation for rewrite
* Rewrite
c Command code
d Data
e Data
c Command code
d Address upper
e Address lower
A8h ( 1 0 1 0 1 0 0 0 )
( D15 . . . . D8 )
( D7 . . . . . D0 )
A4h ( 1 0 1 0 0 1 0 0 )
( 0 0 0 0 0 0 A9 A8 )
(A7 . . . . A0 )
S_RESET
RQ
SCLK
SI
RDY
SO
10101000 D15 **** D0
10100100 000000A9*A0
max 400ns
RDYLG
Note: The RDY signal will go to high within the maximum of two LRCLKs if the RDYLG width
is programmed to ensure a new address to be rewritten within one sampling cycle.
Fig. 8-27 CRAM rewriting preparation and writing
[MS0369-E00]
- 52 -
2004/12