AT87C52X2-RLRUM Atmel, AT87C52X2-RLRUM Datasheet - Page 11
![MCU ROMLESS 32X2 3V 44-VQFP](/photos/6/92/69202/313-44-vqfp_sml.jpg)
AT87C52X2-RLRUM
Manufacturer Part Number
AT87C52X2-RLRUM
Description
MCU ROMLESS 32X2 3V 44-VQFP
Manufacturer
Atmel
Series
87Cr
Datasheet
1.AT80C32X2-RLRUL.pdf
(55 pages)
Specifications of AT87C52X2-RLRUM
Core Processor
8051
Core Size
8-Bit
Speed
40/20MHz
Connectivity
UART/USART
Peripherals
POR
Number Of I /o
32
Program Memory Size
8KB (8K x 8)
Program Memory Type
OTP
Ram Size
256 x 8
Voltage - Supply (vcc/vdd)
4.5 V ~ 5.5 V
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-TQFP, 44-VQFP
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
Data Converters
-
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Application
4184I–8051–02/08
Software can take advantage of the additional data pointers to both increase speed and
reduce code size, for example, block operations (copy, compare, search ...) are well
served by using one data pointer as a ’source’ pointer and the other one as a "destina-
tion" pointer.
ASSEMBLY LANGUAGE
INC is a short (2 bytes) and fast (12 clocks) way to manipulate the DPS bit in the AUXR1
SFR. However, note that the INC instruction does not directly force the DPS bit to a par-
ticular state, but simply toggles it. In simple routines, such as the block move example,
only the fact that DPS is toggled in the proper sequence matters, not its actual value. In
other words, the block move routine works the same whether DPS is '0' or '1' on entry.
Observe that without the last instruction (INC AUXR1), the routine will exit with DPS in
the opposite state.
; Block move using dual data pointers
; Destroys 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,atDPTR ; get a byte from SOURCE
000B A3 INC DPTR ; increment SOURCE address
000C 05A2 INC AUXR1 ; switch data pointers
000E F0 MOVX atDPTR,A ; write the byte to DEST
000F A3 INC DPTR ; increment DEST address
0010 70F6JNZ LOOP ; check for 0 terminator
0012 05A2 INC AUXR1 ; (optional) restore DPS
LOOP:
AUXR1 EQU 0A2H
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