W79E804A/803A/802A
8. SPECIAL FUNCTION REGISTERS
The W79E804 series uses Special Function Registers (SFRs) to control and monitor peripherals and
their Modes. The SFRs reside in the register locations 80-FFh and are accessed by direct addressing
only. Some of the SFRs are bit addressable. This is very useful in cases where users wish to modify a
particular bit without changing the others. The SFRs that are bit addressable are those whose
addresses end in 0 or 8. The W79E804 series contain all the SFRs present in the standard 8052.
However some additional SFRs are added. In some cases the unused bits in the original 8052, have
been given new functions. The list of the SFRs is as follows.
F8
IP1
F0
E8
E0
D8
D0
C8
C0
B8
B0
A8
B
EIE
P0ID
IP1H
ACC
WDCON
PSW
PWMPL
PWMPH
PWM0L
PWM0H
PWM1L PWMCON1
PWM1H
PWM2L
PWM2H
PWM3L
PWM3H
NVMCON
NVMADDR
I2CLK
PWMCON2
PWMCON3
NVMDAT
TA
I2CON
IP0
I2ADDR
SADEN
P0M1
I2DAT
I2STATUS
P2M1
I2TIMER
IP0H
P0M2
P1M1
P1M2
CMP1
P2M2
IE
SADDR
CMP2
A0
P2
KBI
AUXR1
98
90
88
80
SCON
P1
SBUF
DIVM
TH1
TCON
P0
TMOD
SP
TL0
TL1
TH0
CKCON
DPL
DPH
PCON
Table 8-1: Special Function Register Location Table
Note: 1. The SFRs in the column with dark borders are bit-addressable
2. The table is condensed with eight locations per row. Empty locations indicate that these are no registers at these
addresses. When a bit or register is not implemented, it will read high.
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