AK2305 Datasheet, PDF (21/43 Pages) Asahi Kasei Microsystems – Dual PCM CODEC for ISDN TERMINAL ADAPTER

ASAHI KASEI
[AK2305]
TONE GENERATOR
Generates two kinds of tone, 400Hz and 1300Hz.
One of them is selected by TMDn register.
SELECTION OF TONE
Selects 1 tone from 400Hz/1300Hz by TMDn register.
Tone selection register
TMDn
0
1
(n=0,1)
Tone frequency
400Hz
1300Hz
Remarks
Reset
SELECTION OF OUTPUT PIN
VRX0, VRX1, TNOUT is available for Tone output pin by S1-S9 switch.
S1-S9 switch is controlled by each register.
Tone output by switch controlling
Output
circuits
VRX0
TONEGEN0
S1
VRX1
S4
TONEGEN1
S2
S5
AUX
S3
S6
TNOUT
S7
S8
S9
Register setting
“0” : OFF
“1” : ON
Remarks
All “0”
when reset
TONE OUTPUT ENABLE
Inputting “1” to TNOEn, defined tone is output.
Tone Output Enable
TONEn
Output States
0
AGND
1
Tone
AUX INPUT
Input signal from external CPU/Tone generators.
Signals are output on VRXn, TNOUT via VRnR, VRTN.
Output signals are switched onto each pin by S3, S6, and S9 which are controlled by registers.
(See “SELECTION OF OUTPUT PIN” above.)
Must input with an external cap(>0.1uF.)
Input impedance is 200kΩ±25%.
C0029-E-02
21
1999/8