Navigation bar
  Start Previous page
 68 of 156 
Next page End 63 64 65 66 67 68 69 70 71 72 73  

62
BasicX Compatibility Note
In BasicX mode, only a subset of the variables described below is available, being
limited to those that are also present in BasicX.  Those that are available in BasicX
mode are specifically identified in their descriptions.
Register.ResetFlags
Whenever the processor is reset, the cause of the reset is noted and stored in an internal variable that is
available to user programs as Register.ResetFlags.  The bits of the Byte value have the meaning
shown in the table below.
ResetFlags Bit Semantics
Reset Source
Hex Value
WatchDog Reset
&H08
Brown-Out Reset
&H04
External Reset
&H02
Power-On Reset
&H01
The value of this register is set when the processor first begins executing the control program.  The value
is not used by the control program in any manner so you may modify it to suit the needs of your
application.  Note that in some circumstances, two or more of the bits in the table above may be present.
Register.RTCDay
Register.RTCTick
These two register values (both available in BasicX compatibility mode) represent the current state of the
real time clock (RTC).  Register.RTCTick is a Long value that is incremented on each RTC tick (see
Register.RTCTickFrequency).  After 24 hours of continuous execution, it will reach its maximum
value and will then roll over to zero.  At the same time, the value of Register.RTCDay, type
UnsignedInteger, will be incremented.  Day number zero represents January 1, 1999 (for compatibility
with BasicX).  When the system is reset or powered up both of these values are initialized to zero.
Register.RTCFastTick
This Byte value changes twice as fast as Register.RTCTick.  For most purposes, this value should
be considered to be read-only.  Changing it will affect the accuracy of the RTC and may interfere with
normal task switching. 
Register.RTCStopWatch
This UnsignedInteger value is incremented on each RTC tick (see Register.RTCTickFrequency),
the same as Register.RTCTick.  However, you may reset this value to zero at any time to facilitate
simpler elapsed time calculations without affecting the RTC’s timekeeping.  This register variable is
available in BasicX compatibility mode.
Register.RTCTickFrequency
This read-only UnsignedInteger value indicates the number of RTC ticks that will occur per second. 
For all ZX models currently available, the RTC tick frequency is 512Hz.
Previous page Top Next page