C8051F045 View Datasheet(PDF) - Silicon Laboratories

Part Name

Description

Manufacturer

C8051F045

Mixed Signal ISP Flash MCU Family

Silicon Laboratories 

C8051F040/1/2/3/4/5/6/7

SFRPAGE

pushed to

SFRNEXT

SFRNEXT

pushed to

SFRLAST

SFR Page 0x00

Automatically

pushed on stack in

SFRPAGE on PCA

interrupt

0x00

(PCA)

0x02

(ADC2)

0x0F

(Port 5)

SFRPAGE

SFRNEXT

SFRLAST

Figure 12.6. SFR Page Stack Upon PCA Interrupt Occurring During an ADC2 ISR

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 12.7

below.

Rev. 1.5

139

Share Link: