MC68000 MOTOROLA [Motorola, Inc], MC68000 Datasheet - Page 385

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

D.6.7 Serial Interface Configuration
To allow the MC68302 to be tied to the IDL bus, the serial interface (see Figure D-15) must
be configured to the IDL mode. A value of $0C76 written to the SIMR will set the following
configuration: IDL mode, D-channel routed to SCC3, B1-channel routed to SCC1, SCC2
working in NMSI mode (routed to its external pins), and SDS1 enveloping B2-channel (CO-
DEC strobe).
This configuration is suitable for terminal adaptor configuration, in which the non-lSDN ter-
minal is connected to SCC2. The output/input frames of the rate adaption protocol are trans-
mitted/received by SCC1 over B1 channel, and SCC3 handles the signaling over the D-
channel (call establishment, disconnect, etc.). The B2 channel is routed to a CODEC by the
serial data strobe 1 and is used for voice calls
The serial interface mask register allows selection of subrates of the 64-kbps B-channel ca-
pacity by selecting the used bits of the eight B-channel bits.
MOTOROLA
NON-ISDN
TERMINAL
Figure D-15. Serial Interface Configuration
SCC2
MC68302 USER’S MANUAL
MC68302 IMP
HDLC
HDLC
UART
SCC3
SCC1
HANDSET
SDS1
STROBE
B1-CH
D-CH
MC145554
CODEC
B2-CH
MC68302 Applications
MULTIPLEXED
IDL BUS 2B+D
D-35