ZL38001
Data Sheet
In SSI operation, the frame boundary is determined by the rising edge of the ENA1 enable strobe (see Figure 7).
The other enable strobe (ENA2) is used for parsing input/output data and it must pulse within 125 microseconds of
the rising edge of ENA1.
In SSI operation, the enable strobes may be a mixed combination of 8 or 16 BCLK cycles allowing the flexibility to
mix 2’s complement linear data on one port (e.g., Rin/Sout) with companded data on the other port (e.g., Sin/Rout).
Enable Strobe Pin
Designated PCM I/O Port
ENA1
ENA2
Line Side Echo Path (PORT 1)
Acoustic Side Echo Path (PORT 2)
Table 3 - SSI Enable Strobe Pins
2.3 PCM Law and Format Control (LAW, FORMAT)
The PCM companding/coding law used by the ZL38001 is controlled through the LAW and FORMAT pins. ITU-T
G.711 companding curves for µ-Law and A-Law are selected by the LAW pin. PCM coding ITU-T G.711 and Sign-
Magnitude are selected by the FORMAT pin. See Table 4.
BCLK
start of frame (SSI)
PORT1
ENA1
8 or 16 bits
Rin
EC
Sout
8 or 16 bits
PORT2
ENA2
8 or 16 bits
Sin
EC
8 or 16 bits
Rout
outputs = High impedance
inputs = don’t care
Note that the two ports are independent so that, for example, PORT1 can operate with 8-bit enable strobes and PORT2 can operate
with 16-bit enable strobes.
Figure 7 - SSI Operations
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