C8051F040 View Datasheet(PDF) - Silicon Laboratories
Part Name
Description
MFG CO.
'C8051F040' PDF : 328 Pages View PDF
0x0F
(Port 5)
C8051F040/1/2/3/4/5/6/7
SFR Page
Stack SFR's
SFRPAGE
SFRNEXT
SFRLAST
Figure 12.4. SFR Page Stack While Using SFR Page 0x0F To Access Port 5
While CIP-51 executes in-line code (writing values to Port 5 in this example), an ADC2 Window Compara-
tor Interrupt occurs. The CIP-51 vectors to the ADC2 Window Comparator ISR and pushes the current
SFR Page value (SFR Page 0x0F) into SFRNEXT in the SFR Page Stack. The SFR page needed to
access ADC2’s SFR’s is then automatically placed in the SFRPAGE register (SFR Page 0x02). SFRPAGE
is considered the “top” of the SFR Page Stack. Software can now access the ADC2 SFR’s. Software may
switch to any SFR Page by writing a new value to the SFRPAGE register at any time during the ADC2 ISR
to access SFR’s that are not on SFR Page 0x02. See Figure 12.5.
Rev. 1.5
137
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