Intel 8XC196MC Microscope & Magnifier User Manual


 
C-59
REGISTERS
WG_COMPx
WG_COMP
x
x
= 1–3
Address:
Reset State:
1FC2H,1FC4H,1FC6H
0000H
The phase compare (WG_COMP
x
) register controls the duty cycle of each phase. Write a value to
each phase compare register to specify the length of time that the associated outputs will remain
asserted.
Changing the WG_RELOAD value changes both the carrier period and the duty cycle because the
outputs remain asserted for a constant length of time, while the counter takes longer to cycle. To
change the carrier period without changing the duty cycle, you must proportionally change both
WG_RELOAD and WG_COMP
x
at the same time, immediately after the interrupt.
15 0
Compare
Bit
Number
Function
15:0 Compare
These bits determine the length of time that the associated outputs are asserted.
Use the following formulas to calculate output assertion time and duty cycle.
where:
T
OUTPUT
= total time output is asserted, in µs
F
XTAL1
= input frequency on XTAL1 pin, in MHz
multiplier
= 4 for center-aligned modes; 2 for edge-aligned modes
WG_RELOAD = 16-bit WG_RELOAD value WG_COMP
x
WG_COMP
x
= 16-bit WG_COMP
x
value WG_RELOAD
T
OUTPUT
multiplier
WG_COMPx×
F
XTAL1
-----------------------------------------------------------------
=
Duty Cycle
WG_COMPx
WG_RELOAD
--------------------------------------
100%×=