Cal Power TrueWave TW5250, Service Manual

Page: 14 / 84

THEORY OF OPERATION TW SERIES
1-4
1.4 DIGITAL CONTROL BOARD
FIGURE 1-2. DIGITAL CONTROL BOARD BLOCK DIAGRAM
The Digital Control Board is the central controller of the TW system. It handles all
communication with the outside world and the Analog Processor Board. It consists of
the following interfaces:
•
Front panel keypad and display elements
•
GPIB (IEEE 488.2 interface) SCPI Protocol
•
RS-232 (9600 baud, 1 start bit, 8 data bit, no parity, 1 stop bit) SCPI Protocol
•
QSPI for Analog Processor Board interface
The Digital Control Board is controlled by a Motorola 68332 processor, operating with a
16-bit data bus. The processor system memory consists of one 256K x 16 20ns static
RAM, one 256K x 16 90ns FLASH ROM, 64K x 8 120ns PROM and 8K x 8 EEPROM.
The PROM is used during boot for processor execution, the EEPROM is used for
calibration data, the FLASH is used for processor execution, and the RAM is used for
system data storage. For more information on the MC68332 processor, refer to the
Motorola MC68332 User’s Manual.
At power up the 68332 boots from a dedicated PROM. This PROM contains
executable code that allows the FLASH memory to be programmed from data received
either from the GPIB or serial port. During the boot process the FLASH memory is
KEYPAD
DISPLAY
GPIB
RS-232
MC68332
PROCESSOR
SYSTEM
MEMORY
QSPI
Analog
Processor
Board