Customizing The Board 5-8
5.9 Installing Supervisor Utilities
5.9.1
Special Note on Register 201h
IBM PCs use address 201h as the game port. TEKNOR computers utilize this address to
give industrial PC users the greatest amount of I/O addressing space possible. This
ultimately renders the game port unusable.
Hence, some problems may occur with various test software packages that intentionally
write to the game port and leave it with unknown values.
The following table illustrates how TEKNOR computers utilize I/O Register 201h:
TABLE 5-4:
Register 201h
Bit
Function
0
Enable Watchdog (1=enable, R/W bit)
1
Watchdog activate (1-0-1 to toggle, R/W bit)
2
Flash VPP enable (1=VPP 12v, 0=VPP 5v, R/W bit)
3
Enable direction control RS-485
(1=enable RS-485 only, write only)/(Read=PDO
*
Status)
4
Make printer 8 data bits read only
(1=input, 0=output, write only)
5
Select alternate SW1/SW2 (TEK-AT4L+, TEK-AT3L, TEK-AT4L+) (1=select
SW2, read only)
6
Not used
7
Not used
WARNING:
Not all bits are R/W. Therefore, be certain to keep a mirror image of
register 201(hex) when programming it. All bits are 0 after a hardware
RESET or power up condition.
5.9.2
Watchdog Timer
The
Watchdog Timer
is extremely useful in embedded systems where human supervision
is not required. Following a reset, the Watchdog is always disabled. The Watchdog is
enabled once "1" is written in bit 0 at address 201h the first time. When enabled, the
microprocessor must refresh the Watchdog. This is done by writing alternatively "0" and
"1" to bit 1 at address 201h, once every 1.6 seconds to verify proper software execution.
Содержание TEK-AT4L Plus
Страница 7: ...PRODUCT DESCRIPTION 1 PRODUCT OVERVIEW 2 ONBOARD SUBSYSTEMS...
Страница 9: ...Product Overview 1 2 TEK AT4LPLUS Block Diagram...
Страница 26: ...Installing Devices 6 3 CONNECTOR LOCATION...
Страница 35: ...Setting Jumpers 8 3 JUMPER LOCATIONS...
Страница 36: ...Setting Jumpers 8 5 TABLE 8 1 Jumper Settings W1 W11...
Страница 37: ...Setting Jumpers 8 6 TABLE 8 2 Jumper Settings W12 W19 W26...
Страница 38: ...Setting Jumpers 8 7 TABLE 8 3 Jumper Settings W20 W25 SW1 SW2...
Страница 41: ...APPENDICES A PRODUCT SPECIFICATIONS B BOARD DIAGRAMS C CONNECTOR PINOUTS...
Страница 43: ...Board Diagrams B 1 B 1 TEK AT4LPLUS Assembly Diagram Top View...
Страница 44: ...Board Diagrams B 3 B 2 TEK AT4LPLUS Mounting Holes...
Страница 45: ...Board Diagrams B 5 B 3 TEK AT4LPLUS Mechanical Specifications...