MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 391

• Manufacturer Part Number: MC68000
• Manufacturer: MOTOROLA [Motorola, Inc]

D.6.15 MC145554 CODEC Filter
A CODEC is a device that performs voice digitization and reconstruction as well as the band
limiting and smoothing required for PCM systems.
The MC145554 is a Mu-law device that can be tied directly to the IDL bus. The SDS strobe
generated by the MC68302 serial interface can be used to route the CODEC to the proper
B-channel.
The analog interface between the CODEC and the handset shown in Figure D-18 is suitable
for a carbon microphone. If another low-output microphone is used, an amplifier must be in-
cluded to drive the input of the CODEC to the proper levels.
D.7 INTERFACING A MASTER MC68302 TO ONE OR MORE SLAVE
When more than three SCC channels are required in an application, multiple MC68302s can
be used to solve the problem. One possible solution would be to design a board with several
MOTOROLA
MC68302S
ANALOG_OUT
ANALOG_IN
Nibble register 2 allows activation (TE/NT) and deactivation (NT)
of the S/T loop. To activate the loop, write $8 to NR2. To deacti-
vate the loop, write $4 to NR2.
Figure D-18. CODEC/IDL Electrical Connection
MC68302 USER’S MANUAL
MC145554
NOTE
MCLKR
MCLKX
BCLKX
BCLKR
FSR
FSX
DX
DR
SERIAL_DATA_STROBE
IDL_CLOCK ( 2.048 MHz)
DATA TO S/T
DATA FROM S/T
MC68302 Applications
D-41