at89c51ac3-s3sim ATMEL Corporation, at89c51ac3-s3sim Datasheet - Page 25

• Manufacturer Part Number: at89c51ac3-s3sim
• Description: At89c51ac3 Enhanced 8-bit Microcontroller With 64kb Flash Memory
• Manufacturer: ATMEL Corporation

Registers
4383D–8051–02/08
Table 6. PSW Register
PSW (S:8Eh)
Program Status Word Register
Reset Value = 0000 0000b
Table 7. AUXR Register
AUXR (S:8Eh)
Auxiliary Register
Number
Number
CY
Bit
Bit
4-3
7-6
7
7
-
7
6
5
2
1
0
5
Mnemonic Description
Mnemonic Description
RS1:0
AC
Bit
Bit
CY
AC
OV
M0
F0
F1
6
6
P
-
-
Carry Flag
Carry out from bit 1 of ALU operands.
Auxiliary Carry Flag
Carry out from bit 1 of addition operands.
User Definable Flag 0.
Register Bank Select Bits
Refer to Table 4 for bits description.
Overflow Flag
Overflow set by arithmetic operations.
User Definable Flag 1
Parity Bit
Set when ACC contains an odd number of 1’s.
Cleared when ACC contains an even number of 1’s.
Reserved
The value read from these bits are indeterminate. Do not set this bit.
Stretch MOVX control:
the RD/ and the WR/ pulse length is increased according to the value of M0.
M0
0
1
M0
F0
5
5
Pulse length in clock period
6
30
XRS2
RS1
4
4
XRS1
RS0
3
3
XRS0
OV
2
2
EXTRAM
F1
1
1
A0
P
0
0
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