AK7712A-VT Datasheet, PDF (36/87 Pages) Asahi Kasei Microsystems – Built-in 20-bit ADC/DAC Sophisticated Audio DSP

ASAHI KASEI
[AK7712A-VT]
In each command of ALU, input data is processed as follows.
Command
A input
B input
OF ZF SF OV
ALU function
NOP
<<
<1
+
-
1-
1+
||
all "0"
-24bits+1,all"0"
A
A
A
A
A
B
B
B
inversion+1
+4∼-23bits="1"
-24∼-29bits="0"
-23bits+1, all "0"
all "0"
not change
{{{{
{{{{
{{{{
{{{{
{ { { RE
{ { { RE
{{{{
/20
A
-20bits+1, all"0"
{{{{
/18
-18bits+1, all"0"
{{{{
/16
-16bits+1, all"0"
{{{{
$
A,+1∼+4bits="0"
B
× { × RE
&
A,+1∼+4bits="0"
B
× { × RE
#
A,+1∼+4bits="0"
B
× { × RE
!
inversion
all "0"
× { × RE
{: Flag is effective. ×: Don't care. RE: Reset of overflow register
+
+
+
+
+
+
positive: +
negative: invertion + 1
+
OR
AND
EXOR
NOT
About the timing of ALU, the input of B register actions always, but when ALU is NOP, the value of ACC and flag
are not changed. It becomes possible to output the result to DBUS 2 steps later .
0180-E-02
- 36 -
1997/12