AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 20

• Manufacturer Part Number: AT89C51RE2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RE2

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Spi: 1
• Uart: 2
• Sram (kbytes): 8.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/OCD
• Watchdog: Yes

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AT89C51RE2
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.
0010 70F6JNZ LOOP ; check for 0 terminator
0012 05A2 INC AUXR1 ; (optional) restore DPS
7663E–8051–10/08