Technical Manual

6-2
The ADSIC (U406) is basically a support IC for the DSP. It provides,
among other things, the interface from the digital world of the DSP to
the analog world. The ADSIC also provides interrupt control for the
DSP processing algorithms and some memory management. The
configuration programming of the ADSIC is performed by the MCU.
However, some components of the ADSIC are controlled through a
parallel memory mapped register bank by the DSP.
In the receive mode, The ADSIC (U406) acts as an interface with the
ABACUS IC, which can provide IF data samples directly to the DSP for
processing. Or, the IF data can be filtered and discriminated by the
ADSIC and data provided to the DSP as raw discriminator sample data.
The latter mode, with the ADSIC performing the IF filtering and
discrimination, is the typical mode of operation.
SSI
SERIAL
EXTAL MODB MODA
HC11/DSP
Interface
D0-D23
BUS
CONTROL
A0-A15
U405
DSP56001
SCI
SERIAL
Encryption
Interface
To Secure Board
To Controller Board
Host
Port
System
Clock
Gata Array
Logic
ABACUS Rx
Interface
Tx D/A
MAI
SDO
General
Purpose I/O
Speaker
D/A
Microphone
A/D
Serial
Config.
U406
ADSIC
ABACUS
Interface
To/From
Controller
Board
Modulation
Out
U403
32Kx8
SRAM
U404
256Kx8
FLASH
U402
32Kx8
SRAM
U401
32Kx8
SRAM
HC11
SPI Bus
MAEPF-25999-O
Figure 6 Vocoder Board