CDB6420 Cirrus Logic Inc, CDB6420 Datasheet - Page 43

• Manufacturer Part Number: CDB6420
• Description: Development Kit
• Manufacturer: Cirrus Logic Inc

Specifications of CDB6420

• Silicon Manufacturer: Cirrus Logic
• Application Sub Type: Speakerphone
• Kit Application Type: Audio / Video / TV
• Silicon Core Number: CS6420
• Kit Contents: Board
• Kit Features: Analog And Digital Patch Area
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

CDB6420
Figure 5. CS6420 Connection Diagram
using APO_IN as an input. This connects the sig-
nal path appropriately. The control bit in the soft-
ware (Mic) must be set to APO as well. When
using MICIN as the acoustic side input source,
HDR1 must be in the PREAMP ON (3-4) position,
and the Mic bit in the software should be set to API.
The test loops labeled API and APO are provided to
allow easy probing of the pins of the same name. The
maximum signal present at APO should be 2.8 V
pp
with TGain (see the Software section) set to 0 dB.
Parallel Port Interface
Figure 6 shows the parallel port interface of the
CDB6420 that connects to a PC’s parallel port. The
74HCT541 buffer serves to protect the CS6420
from any damaging surges. The buffer is socketed
for easy replacement. Four of the parallel port data
lines are used to control the microcontroller interface
pins of the CS6420. The RC network serves to min-
Figure 7. Grounds
imize the ringing common to HCT devices. Test
loops are provided for easy oscilloscope access.
DS205DB1
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