C8051F54X_14 Datasheet, PDF (94/275 Pages) Silicon Laboratories – Mixed Signal ISP Flash MCU Family

C8051F54x
SFRNEXT
popped to
SFRPAGE
SFRLAST
popped to
SFRNEXT
SFR Page 0x00
Automatically
popped off of the
stack on return from
interrupt
0x00
(SPI0)
0x0F
(SMB0ADR)
SFRPAGE
SFRNEXT
SFRLAST
Figure 12.5. SFR Page Stack Upon Return From PCA Interrupt
On the execution of the RETI instruction in the SPI0 ISR, the value in SFRPAGE register is overwritten
with the contents of SFRNEXT. The CIP-51 may now access the SMB0ADR register as it did prior to the
interrupts occurring. See Figure 12.6.
94
Rev. 1.1