at89c51re2-slsem ATMEL Corporation, at89c51re2-slsem Datasheet - Page 19

• Manufacturer Part Number: at89c51re2-slsem
• Description: At89c51re2 8-bit Flash Microcontroller
• Manufacturer: ATMEL Corporation

7663B–8051–03/07
Table 16. AUXR1 register
AUXR1- Auxiliary Register 1(0A2h)
Reset Value: XX0X XX0X0b
Not bit addressable
Note:
ASSEMBLY LANGUAGE
Number
EES
; Block move using dual data pointers
; Modifies DPTR0, DPTR1, A and PSW
; note: DPS exits opposite of entry state
; unless an extra INC AUXR1 is added
;
00A2
;
0000 909000MOV DPTR,#SOURCE ; address of SOURCE
0003 05A2 INC AUXR1 ; switch data pointers
0005 90A000 MOV DPTR,#DEST ; address of DEST
0008
0008 05A2 INC AUXR1 ; switch data pointers
000A E0 MOVX A,@DPTR ; get a byte from SOURCE
000B A3 INC DPTR ; increment SOURCE address
000C 05A2 INC AUXR1 ; switch data pointers
000E F0 MOVX @DPTR,A ; write the byte to DEST
000F A3 INC DPTR ; increment DEST address
Bit
7
7
6
5
4
3
2
1
0
*Bit 2 stuck at 0; this allows to use INC AUXR1 to toggle DPS without changing GF3.
LOOP:
AUXR1 EQU 0A2H
Mnemonic Description
DPS
EES
SP9
GF2
SP9
Bit
U2
6
0
-
-
Enable Extended Stack
This bit allows the selection of the stack extended mode.
Set to enable the extended stack
Clear to disable the extended stack (default value)
Stack Pointer 9th Bit
This bit has no effect when the EES bit is cleared.
Set when the stack pointer belongs to the XRAM memory space
Cleared when the stack pointer belongs to the 256bytes of internal RAM.
P4 bit addressable
Clear to map SCON_1 register at C0h sfr address
Set to map P4 port register at C0h address.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
This bit is a general purpose user flag. *
Always cleared.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Data Pointer Selection
Cleared to select DPTR0.
Set to select DPTR1.
U2
5
4
-
GF2
3
2
0
1
-
DPS
0
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