AT89C51AC3 Atmel Corporation, AT89C51AC3 Datasheet - Page 26

• Manufacturer Part Number: AT89C51AC3
• Manufacturer: Atmel Corporation

Specifications of AT89C51AC3

• Flash (kbytes): 64 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 62.5
• Sram (kbytes): 2.25
• Eeprom (bytes): 2048
• Self Program Memory: API
• Operating Voltage (vcc): 3.0 to 5.5
• Timers: 4
• Isp: UART
• Watchdog: Yes

26
AT89C51AC3
Reset Value = X001 0100b
Not bit addressable
Table 8. AUXR1 Register
AUXR1 (S:A2h)
Auxiliary Control Register 1
Reset Value = XXXX 00X0b
Number
Number
Bit
Bit
4-2
7-6
7
-
1
0
5
4
3
2
1
0
Mnemonic Description
Mnemonic Description
EXTRAM
ENBOOT
XRS1-0
DPS
GF3
Bit
Bit
A0
6
-
0
-
-
-
ERAM size:
Accessible size of the ERAM
XRS 2:0 ERAM size
000
001
010
011
100
101
110
111
Internal/External RAM (00h - FFh)
access using MOVX @ Ri/@ DPTR
0 - Internal ERAM access using MOVX @ Ri/@ DPTR.
1 - External data memory access.
Disable/Enable ALE)
0 - ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2
mode is used)
1 - ALE is active only during a MOVX or MOVC instruction.
Reserved
The value read from these bits is indeterminate. Do not set these bits.
Enable Boot Flash
Set this bit for map the boot Flash between F800h -FFFFh
Clear this bit for disable boot Flash.
Reserved
The value read from this bit is indeterminate. Do not set this bit.
General-purpose Flag 3
Always Zero
This bit is stuck to logic 0 to allow INC AUXR1 instruction without affecting GF3
flag.
Reserved for Data Pointer Extension.
Data Pointer Select Bit
Set to select second dual data pointer: DPTR1.
Clear to select first dual data pointer: DPTR0.
ENBOOT
5
256 Bytes
512 Bytes
768 Bytes
1792 Bytes
2048 Bytes (default configuration after reset)
Reserved
1024 Bytes
Reserved
4
-
GF3
3
2
0
4383D–8051–02/08
1
-
DPS
0