AK2305 Datasheet, PDF (10/43 Pages) Asahi Kasei Microsystems – Dual PCM CODEC for ISDN TERMINAL ADAPTER

ASAHI KASEI
[AK2305]
Long Frame Sync(LF) Short Frame Sync(SF)
AK2305 automatically decides whether Long Frame or Short Frame should be selected, by monitoring the high
level period of First FS.
Period of First FS =”H”
more than 2 clock of BCLK
1 clock of BCLK
Frame type
LF
SF
INTERFACE TIMING
<2ch Multiplex>
PCM data of both channel are interfaced by the DX0 and DR0(DX1 and DR1 are not used) at the format of
8bits in the period of 1 frame(125us) which synchronizes with the FSn(n=0,1). In the period of 1frame, 64 time
slots can be assigned at the maximum (in case of BCLK=4.096MHz). The number of the time slots is BCLK/64k.
The time slot assignment of CH0 and CH1 is decided by FS0 and FS1. In the mode of LF and SF, second FS(not
first FS) must be delayed or fast at least (8/BCLK) x n: (n=1 - 63) from the first FS.
LongFrame
FS0
BCLK
DX0
1 2 3 4 5 6 78
DR0
Don’t
care
1
2
3
4
5
6
7
8
Don’t care
ShortFrame
FS0
BCLK
DX0
DR0
Don’t
care
1 2 3 4 5 6 78
12345678
Don’t care
BCLK=4096kHz ( First FS = FS0 )
FS0
FS1
SLOT
DX0
DR0
1
2
3
4
ch0
output
ch0
input
ch1
output
ch1
input
63 64 1
2
3
4
ch0
output
ch0
input
ch1
output
ch1
input
C0029-E-02
10
1999/8