Motorola ASTRO XTS 3000 Service Manual page 50

U401
32Kx8
SRAM
U402
32Kx8
SRAM
U403
32Kx8
SRAM
U404
256Kx8
FLASH
Gata Array
Logic
General
Purpose I/O
Speaker
D/A
6-2
A0-A15
U405
D0-D23
DSP56001
BUS
CONTROL
System
Tx D/A
Clock
U406 ABACUS Rx
Interface
ADSIC
Microphone Serial
Config.
A/D
Figure 6-6 Vocoder Board
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.
HC11/DSP
Interface
Host
Port
SCI
Encryption
SERIAL
Interface
SSI
SERIAL
To Controller Board
To Secure Board
Modulation
Out
ABACUS
Interface
To/From
HC11
Controller
SPI Bus
Board
MAI
SDO
MAEPF-25999-O