©
National Instruments Corporation
4-1
Chapter
4
Theory of Operation
This chapter contains a functional overview of the DAQPad-6507/6508
devices and explains the operation of each functional unit making up the
DAQPad-6507 or DAQPad-6508.
The block diagram in Figure 4-1 illustrates the key functional components
of the DAQPad-6507/6508 devices.
Figure 4-1. DAQPad-6507/6508 Devices Block Diagram
2
3
Data
+5 V
8
8
8
8
8
8
8
8
8
8
8
8
Power Supply
Controls
Firmware
EEPROM
SRAM
Serial
Configuration
EEPROM
External Power
5 V Supply
Power Supply
Controls
Power Supply
Switch
Port A
Port B
Port C
Terminal Blocks (100 POS)
USB Interface
82C55
PPI (A)
82C55
PPI (B)
82C55
PPI (C)
82C55
PPI (D)
82C53
Timer
500 mA
Port A
Port A
Port A
Port B
Port B
Port B
Port C
6
6
6
6
Control Lines
Control Lines
Control Lines
Control Lines
Port C
Port C
USB Microcontroller
Intel 8x930AX
Serial EEPROM
Configuration Port
Interrupt
Request
Serial Port
Interface
Bus
Interface
FPGA
Power Supply
Controls
Interrupt
Controls
Wait State
Controls
Address/Data
Bus
Address/Data
Address/Data
Address/Data
Address/Data
Address/Data
Address/Data
