TS80C51RA2-VCA Atmel, TS80C51RA2-VCA Datasheet - Page 16

• Manufacturer Part Number: TS80C51RA2-VCA
• Description: IC MCU 8BIT 256BYTE 40MHZ 40-DIP
• Manufacturer: Atmel
• Series: 80Cr

Specifications of TS80C51RA2-VCA

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 40/30MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Type: ROMless
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Program Memory Size: -
• Data Converters: -

6. Application
16
AT/TS8xC51Rx2
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 "destination" 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 particular 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 instruc-
tion (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 LOOP:
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
0010 70F6JNZ LOOP ; check for 0 terminator
0012 05A2 INC AUXR1 ; (optional) restore DPS
AUXR1 EQU 0A2H
4188F–8051–01/08