CS8406 Cirrus Logic, CS8406 Datasheet - Page 36

• Manufacturer Part Number: CS8406
• Description: 192 KHZ DIGITAL AUDIO INTERFACE TRANSMITTER
• Manufacturer: Cirrus Logic

CS8406
12.APPLICATIONS
12.1 Reset, Power Down and Start-up
When RST is low, the CS8406 enters a low power mode and all internal states are reset, includ-
ing the control port and registers, and the outputs are disabled. In Software mode when RST is
high, the control port becomes operational and the desired settings should be loaded into the
control registers. Writing a 1 to the RUN bit will then cause the part to leave the low power state
and begin operation. In Hardware mode when RST is high, the part will automatically leave the
low power state and begin operation.
12.2 ID Code and Revision Code
The CS8406 has a register that contains a four-bit code to indicate that the addressed device is
a CS8406. This is useful when other CS84XX family members are resident in the same or similar
systems, allowing common software modules.
The CS8406 four-bit revision level code is also available. This allows the software driver for the
CS8406 to identify which revision of the device is in a particular system, and modify its behavior
accordingly. To allow for future revisions, it is strongly recommended that the revision code is
read into a variable area within the microcontroller, and used wherever appropriate as revision
details become known.
12.3 Power Supply, Grounding, and PCB layout
The CS8406 operates from a VD = +3.3 V or +5.0 V and VL = +3.3 V or +5.0 V supply. These
supplied may be set independently. Follow normal supply decoupling practices, see Figure 5 and
Figure 6. The VD and VL supplies should be decoupled with a 0.1 µ F capacitor to GND to mini-
mize AES3 transmitter induced transients.
Extensive use of power and ground planes, ground plane fill in unused areas and surface mount
decoupling capacitors are recommended. Decoupling capacitors should be mounted on the
same side of the board as the CS8406 to minimize inductance effects, and all decoupling capac-
itors should be as close to the CS8406 as possible.
12.4 Synchronization of Multiple CS8406s
The AES3 transmitters of multiple CS8406s can be synchronized if all devices share the same
master clock, TCBL, and RST signals. The TCBL pin is used to synchronize multiple CS8406
AES3 transmitters at the channel status block boundaries. One CS8406 must have its TCBL set
to master; the others must be set to slave TCBL. Alternatively, TCBL can be derived from exter-
nal logic, whereby all CS8406 devices should be set to slave TCBL.
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