Sfr Definition 11.4. Sfrnext: Sfr Next Register; Sfr Definition 11.5. Sfrlast: Sfr Last Register - Silicon Laboratories C8051F12 Series Manual

C8051F120/1/2/3/4/5/6/7 C8051F130/1/2/3

SFR Definition 11.4. SFRNEXT: SFR Next Register

R/W R/W
Bit7 Bit6
Bits7–0: SFR Page Stack Bits: SFR page context is retained upon interrupts/return from interrupts in
a 3 byte SFR Page Stack: SFRPAGE is the first entry, SFRNEXT is the second, and SFR-
LAST is the third entry. The SFR stack bytes may be used alter the context in the SFR Page
Stack, and will not cause the stack to 'push' or 'pop'. Only interrupts and return from inter-
rupts cause pushes and pops of the SFR Page Stack.
Write: Sets the SFR Page contained in the second byte of the SFR Stack. This will cause
the SFRPAGE SFR to have this SFR page value upon a return from interrupt.
Read: Returns the value of the SFR page contained in the second byte of the SFR stack.
This is the value that will go to the SFR Page register upon a return from interrupt.

SFR Definition 11.5. SFRLAST: SFR Last Register

R/W R/W
Bit7 Bit6
Bits7–0: SFR Page Stack Bits: SFR page context is retained upon interrupts/return from interrupts in
a 3 byte SFR Page Stack: SFRPAGE is the first entry, SFRNEXT is the second, and SFR-
LAST is the third entry. The SFR stack bytes may be used alter the context in the SFR Page
Stack, and will not cause the stack to 'push' or 'pop'. Only interrupts and return from inter-
rupts cause pushes and pops of the SFR Page Stack.
Write: Sets the SFR Page in the last entry of the SFR Stack. This will cause the SFRNEXT
SFR to have this SFR page value upon a return from interrupt.
Read: Returns the value of the SFR page contained in the last entry of the SFR stack.
R/W R/W R/W
Bit5 Bit4 Bit3
R/W R/W R/W
Bit5 Bit4 Bit3
Rev. 1.4
R/W R/W R/W
Bit2 Bit1 Bit0
SFR Address:
SFR Page:
R/W R/W R/W
Bit2 Bit1 Bit0
SFR Address:
SFR Page:
Reset Value
00000000
0x85
All Pages
Reset Value
00000000
0x86
All Pages
143