AN2113 Freescale Semiconductor / Motorola, AN2113 Datasheet - Page 11

• Manufacturer Part Number: AN2113
• Description: AN2113 Multichannel Voice Coding System on the RTXC Operating System
• Manufacturer: Freescale Semiconductor / Motorola

DSP communicates with the multichannel board via the Enhanced Synchronous Serial Interface 0 (ESSI0)
port on the EVM. Each codec on the board executes A/D or D/A operations for two channels of audio data
(stereo audio requires two channels). Four audio codecs are provided for A/D and D/A conversion of the
audio inputs to be processed by the DSP. Therefore, up to eight audio channels can be sent through the
codec board to the DSP device. Figure 8 shows the primary multichannel board components.
Table 1 shows the signal connection table between the EVM and the multichannel board. Immediately
after power-up, the DSP is the master of the connection and uses its GPIO lines to signal the codec that it is
sending control information. Once the master codec (Codec 1) receives the control words, the connection is
reset and the master codec provides the clock for the subsequent data transmission between the EVM and
the multichannel board.
I/O Jacks for
Codec 4
J12
J13
Stereo Out
Left In
Right In
J11
Power Regulators
for 5 V and 3.3 V
EVM ESSI0 Signals
Freescale Semiconductor, Inc.
POWER
9V DC Input
Codec 4
CS4215
J10
I/O Jacks for Codec 3
For More Information On This Product,
Left
In
SCK1
SRD1
U13
GPIO
STD1
GPIO
SC11
GND
J9
Multichannel Voice Coding System
Right
Go to: www.freescale.com
In
Figure 8. Multichannel Board
Table 1. Signal Connection
Pin 1
J8
Stereo
Codec 3
CS4215
Out
U11
S1
J7
I/O Jacks for Codec 2
Left
Multichannel Board Codec Signals
In
Pin 1
CS4215
Codec 2
J6
Right
In
U12
J5
Stereo
I/O Connector
Out
SDOUT
74HCT244
RESET
FSYNC
SCLK
SDIN
GND
To ESSI
D/C
74HCT04
CS4215
Codec 1
Stereo Out
J4
Left
U10
I/O Jacks for
In
J2
Codec 1
Right
In
System Overview
J3
11