C8051F120-TB Silicon Laboratories Inc, C8051F120-TB Datasheet - Page 140

• Manufacturer Part Number: C8051F120-TB
• Description: BOARD PROTOTYPING W/C8051F120
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F120-TB

• Contents: Board
• Processor To Be Evaluated: C8051F12x and C8051F13x
• Interface Type: USB
• Silicon Manufacturer: Silicon Labs
• Core Architecture: 8051
• Silicon Core Number: C8051F120
• Silicon Family Name: C8051F12x
• Kit Contents: Board
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F120
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

C8051F120/1/2/3/4/5/6/7
C8051F130/1/2/3
On exit from the PCA interrupt service routine, the CIP-51 will return to the ADC2 Window Comparator
ISR. On execution of the RETI instruction, SFR Page 0x00 used to access the PCA registers will be auto-
matically popped off of the SFR Page Stack, and the contents of the SFRNEXT register will be moved to
the SFRPAGE register. Software in the ADC2 ISR can continue to access SFR’s as it did prior to the PCA
interrupt. Likewise, the contents of SFRLAST are moved to the SFRNEXT register. Recall this was the
SFR Page value 0x0F being used to access Port 5 before the ADC2 interrupt occurred. See Figure 11.8
below.
140
Figure 11.7. SFR Page Stack Upon PCA Interrupt Occurring During an ADC2 ISR
Figure 11.8. SFR Page Stack Upon Return From PCA Interrupt
SFRNEXT
SFRNEXT
SFRLAST
SFRLAST
SFRPAGE
popped to
SFRPAGE
SFRNEXT
pushed to
SFRNEXT
popped to
pushed to
stack on return from
SFRPAGE on PCA
pushed on stack in
popped off of the
SFR Page 0x00
(ADC2)
(Port 5)
SFR Page 0x00
(ADC2)
(Port 5)
Automatically
Automatically
(PCA)
0x0F
0x02
0x0F
0x00
0x02
interrupt
interrupt
Rev. 1.4
SFRPAGE
SFRNEXT
SFRPAGE
SFRLAST
SFRNEXT
SFRLAST