AT87C52X2-3CSUV Atmel, AT87C52X2-3CSUV Datasheet - Page 10
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AT87C52X2-3CSUV
Manufacturer Part Number
AT87C52X2-3CSUV
Description
Microcontrollers (MCU) Microcontroller
Manufacturer
Atmel
Datasheet
1.AT87C52X2-3CSUV.pdf
(55 pages)
Specifications of AT87C52X2-3CSUV
Data Bus Width
8 bit
Program Memory Type
EPROM
Program Memory Size
8 KB
Data Ram Size
256 B
Interface Type
UART
Maximum Clock Frequency
30 MHz
Number Of Programmable I/os
32
Number Of Timers
3 bit
Operating Supply Voltage
5 V
Maximum Operating Temperature
+ 70 C
Mounting Style
Through Hole
Package / Case
PDIL-40
Minimum Operating Temperature
0 C
Lead Free Status / Rohs Status
No
Dual Data Pointer
Register (Ddptr)
Figure 3. Use of Dual Pointer
10
TS8xCx2X2
7
AUXR1(A2H)
DPS
0
The additional data pointer can be used to speed up code execution and reduce code
size in a number of ways.
The dual DPTR structure is a way by which the chip will specify the address of an exter-
nal data memory location. There are two 16-bit DPTR registers that address the external
memory, and a single bit called
DPS = AUXR1/bit0 (See Table 5.) that allows the program code to switch between them
(Refer to Figure 3).
Table 4. AUXR1: Auxiliary Register 1
Reset Value = XXXX XXX0
Not bit addressable
Number
Bit
7
-
7
6
5
4
3
2
1
0
DPH(83H) DPL(82H)
Mnemonic
DPS
GF3
Bit
6
-
0
-
-
-
-
-
DPTR1
Description
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
This bit is a general purpose user flag
Reserved
Always stuck at 0
Reserved
The value read from this bit is indeterminate. Do not set this bit.
Data Pointer Selection
Clear to select DPTR0.
Set to select DPTR1.
DPTR0
5
-
4
-
GF3
3
External Data Memory
2
0
1
-
4184I–8051–02/08
DPS
0