Miscellaneous, Real time clock (rtc), User gpio interface – Ampro Corporation 420 User Manual
Page 47: Real time clock (rtc) user gpio interface
Chapter 3
Hardware
CoreModule 420
Reference Manual
41
Miscellaneous
Real Time Clock (RTC)
The CoreModule 420 contains a Real Time (time of day) Clock (RTC), which can be backed up with an
external Lithium Battery. The CoreModule 420 will function without a battery in those environments,
which prohibit inclusion of batteries. The CoreModule 420 will also continue to operate after the battery
life has been exceeded. Under these conditions all setup information is restored from the onboard Flash
memory during POST along with the default date and time information.
NOTE
Some operating systems require a valid default date and time to function.
User GPIO Interface
The CoreModule 420 provides GPIO pins for customer use and the signals are routed to connector J8.
An example of how to use the GPIO pins is provided in the Miscellaneous Source Code Examples
subdirectory, under the CoreModule 420 Software menu on the CoreModule 420 Doc & SW CD-ROM
(CD-ROM\Software\Misc\GPIO).
CAUTION
To prevent a system crash, or render the CoreModule 420 BIOS
unusable, do not attempt to use the master GPIO pins (GPIOs 0-7).
The STPC Atlas processor has two GPIO blocks, master and slave.
The slave GPIO pins are reserved for customer applications. The
master GPIO pins are dedicated for BIOS use to control on-board
peripherals. The master GPIO pins can not be used for customer
applications.
The example program can be built by using the make.bat file. This produces a 16-bit DOS executable
application, gpio.exe, which can be run on the CoreModule 420 to demonstrate the use of GPIO pins.
For more information about the GPIO pin operation, refer to the Programming Manual for the STPC
Atlas processor at:
Table 3-18. User GPIO Interface Pin/Signal Descriptions (J8)
Pin #
Signal
Description
1
GPIO8
User defined
2
GPIO9
User defined
3
GPIO10
User defined
4
GPIO11
User defined
5
GPIO12
User defined
6
GPIO13
User defined
7
GPIO14
User defined
8
GPIO15
User defined
9
GND
Ground
10
GND
Ground
Note: The shaded area denotes ground.